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Coordinate Geometry

Class 9th Mathematics RS Aggarwal And V Aggarwal Solution
Exercise 6a
  1. Write down the coordinates of each of the points A, B, C, D, E shown below:…
  2. Draw the lines X OX and YOY as the coordinate axes on a paper and plot the…
  3. On which axis do the following points lie? (i) (7, 0) (ii) (0, -5) (iii) (0, 1)…
  4. In which quadrant do the given points lie? (i) (-6, 5) (ii) (-3, -2) (iii) (2,…
  5. Draw the graph of the equation, y = x+1
  6. Draw the graph of the equation, y = 3x+2
  7. Draw the graph of the equation, y = 5x-3
  8. Draw the graph of the equation, y = 3x
  9. Draw the graph of the equation, y = - x
Cce Questions
  1. The point lies P (-5, 3) inA. quadrant I B. quadrant II C. quadrant III D. quadrant IV…
  2. The point Q (4, -6) lies inA. quadrant I B. quadrant II C. quadrant III D. quadrant IV…
  3. The point Q (0, -4) liesA. quadrant II B. quadrant IV C. on the x-axis D. on the y-axis…
  4. The point B (8, 0) liesA. quadrant I B. quadrant IV C. on the x-axis D. on the y-axis…
  5. The point C(-6, 0) liesA. quadrant II B. quadrant III C. on the x-axis D. on the y-axis…
  6. The point at which the two coordinate axes meet is calledA. the abscissa B. the…
  7. If x 0 and y 0, then the point (x, y) lies inA. quadrant I B. quadrant II C. quadrant…
  8. The points (other than the origin) for which the abscissa is equal to the ordinate lie…
  9. The point in which abscissa and ordinate have different signs will the inA. quadrant I…
  10. The perpendicular distance of the point A (7, 5) from y-axis isA. 7 units B. 5 units…
  11. A point both of whose coordinates are negative lies inA. quadrant I B. quadrant II C.…
  12. Abscissa of a point is positive inA. quadrant I only B. quadrant II only C. quadrant I…
  13. The coordinates of two points are and then (abscissa of A) - (abscissa of B) = ?A. 1…
  14. The points A(2, -2), B(3, - 3), C(4, - 4) and D(5, -5) all lie inA. quadrant II B.…
  15. Which of the points A(0, 6), B(-2, 0), C(0, - 5) D(3, 0) and E(1, 2) does not lie on…
  16. The signs of abscissa and ordinate of a point in quadrant II are respectivelyA. (+, -)…
  17. Which of the following points does not lie on the line y = 3x + 4?A. (1, 7) B. (2, 10)…
  18. Which of the following points lies on the line y = 2x + 3?A. (2, 8) B. (3, 9) C. (4,…
  19. If a 0 and b 0, then the point P(a, b) lies inA. quadrant IV B. quadrant II C.…
  20. The perpendicular distance of the point P(4, 3) from the y-axis isA. 3 units B. 4…
  21. The area of the ΔOAB with O(0, 0), A(4, 0) and B(0, 6) isA. 8 sq units B. 12 sq units…
  22. The area of the ΔOPQ with O(0, 0), P(1, 0) and Q(0, 1) isA. 1 sq unit B. 1/2 sq unit…
  23. Consider the three statements given below: I. Any point on x-axis is of the form…
  24. Assertion (A) Reason (R) The point p(-3,0) lies on x-axis. Every point on x-axis is of…
  25. Assertion (A) Reason (R) The point O (0,0) lies in quadrant I. The point O(0,0) lies…
  26. Assertion (A) Reason (R) The point p(-6,-4) lies in quadrant III. The signs of points…
  27. Assertion (A) Reason (R) If a b then (a, b) (b, a) (4,-3) lies in quadrant IV. The…
  28. Write whether the following statements are true or false? (i) The point p (6 , 0) lies…
  29. State whether true or false: (i) The mirror image of the point a (4 , 5) in the x-axis…
  30. Write whether the following statements are true or false: A. The point (-5, 0) lies on…
  31. Column I Column II (a) Equation of x-axis is (p) (a,0) (b) Equation of y-axis is (q) y…
  32. Column I Column II (a) The point A (-3, 0) lies on (p) y-axis (b) The point B (-5, -1)…
  33. Without plotting the given points on a graph paper indicate the quadrants in which…
  34. Plot the point P(-6, 6) on a graph paper. Draw PL ⊥ x-axis and PM ⊥ y-axis. Write the…
  35. Plot the points A(-5, 2), B(3, -2), C(-4, -3) and D(6, 0) on a graph paper.…
  36. The three vertices of ΔABC are A(1, 4), B(-2, 2) and C(3, 2). Plot these points on a…
  37. The three vertices of a rectangle ABCD are A(2, 2), B(-3, 2) and C(-3, 5). Plot these…
  38. The three vertices of a rectangle ABCD are A(3, 2), B(-2, 2) and C(3, -3). Plot these…
  39. From the figure given below write each of the following: (i) The coordinates of point…
Formative Assessment (unit Test)
  1. If x 0 and y 0, then the point (x, y) lies inA. quadrant I B. quadrant II C. quadrant…
  2. Which point does not lie in any quadrant?A. (3, -6) B. (-3, 4) C. (5, 7) D. (0, 3)…
  3. The area of ΔAOB having vertices A(0,6) , O(0,0) and B(6,0) isA. 12 sq units B. 36 sq…
  4. Read the statements given below and choose the correct answer: I. Any point on x-axis…
  5. Which of the following points does not lie on the line 3y = 2x - 5?A. (7, 3) B. (1, -1)…
  6. Plot each of the following points on a graph paper: A(3, -5), B(-5, -2), C(-6, 1) and…
  7. If 2y = 3 - 5x, find the value of y when x = -1.
  8. On which axis does the point A(0, -4) lie?
  9. In which quadrant does the point B(-3, -5) lie?
  10. What is the perpendicular distance of the point P(-2, -3) from the y-axis?…
  11. At what point do the coordinate axes meet?
  12. For each of the following write true or false: (i) The point (4 , 0) lies in quadrant…
  13. Taking a suitable scale, plot the following points on a graph paper: x -4 -2 5 0 3 -5…
  14. Read the graph paper given below and answer the following: (i) Write the points whose…
  15. (i) Write the mirror image of the point (2, 5) in the x-axis. (ii) Write the mirror…
  16. Without plotting the points on a graph paper indicate the quadrant in which they lie:…
  17. Which of the following points do not lie on x-axis? (i) A(0, 6) (ii) B(2, 0) (iii)…
  18. Three vertices of a rectangle ABCD are A(3, 1), B(-3, 1) and C(-3, 3). Plot these…
  19. Write the coordinates of vertices of a rectangle OABC, where O is the origin, length…
  20. Plot the points A(2, 5), B(-2, 2) and C(4, 2) on a graph paper. Join AB, BC and AC.…

Exercise 6a
Question 1.

Write down the coordinates of each of the points A, B, C, D, E shown below:



Answer:

Co-ordinates of A, B, C, D and E are as follows,


A(-6 , 5 ) , B (5 , 4) , C(-3 , 2) , D (-2 , 2) , E(-1 , 4)



Question 2.

Draw the lines X’ OX and YOY’ as the coordinate axes on a paper and plot the following points on it.

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(vii)

(viii)


Answer:



Question 3.

On which axis do the following points lie?

(i) (7, 0)

(ii) (0, -5)

(iii) (0, 1)

(iv) (-4, 0)


Answer:

(i) (7, 0) lies on X-axis.


(ii) (0, -5) lies on negative or Y-axis.


(iii) (0, 1) lies on positive Y-axis.


(iv) (-4, 0) lies on negative X-axis.



Question 4.

In which quadrant do the given points lie?

(i) (-6, 5)

(ii) (-3, -2)

(iii) (2, -9)


Answer:

(i) In given points X co-ordinate is negative and Y co-ordinate is positive, Hence, (-6, 5) lies in 2nd quadrant.


(ii) In given points X co-ordinate is negative and Y co-ordinate is also negative, Hence, (-3, -2 ) lies in 3rd quadrant.


(iii) In given points X co-ordinate is positive and Y co-ordinate is negative, Hence, (2, -9) lies in 4th quadrant.



Question 5.

Draw the graph of the equation,


Answer:

The given equation is y = x + 1 ……….(i)


Now,


By putting x = 0 in equation (i), we get y = 1


By putting x = 1 in equation (i), we get y = 2


By putting x = 2 in equation (i), we get y = 3


By putting x = 3 in equation (i), we get y = 4


A table is form such that:





Question 6.

Draw the graph of the equation,


Answer:

The given equation is y = 3x + 2 …….(i)


Now,


By putting x = -1 in equation (i), we get y = -1


By putting x = 0 in equation (i), we get y = 2


By putting x = 1 in equation (i), we get y = 5


By putting x = 2 in equation (i), we get y = 8


A table is form such that:





Question 7.

Draw the graph of the equation,


Answer:

The given equation is y = 5x - 3 …….(i)


Now,


By putting x = 0 in equation (i), we get y = -3


By putting x = 1 in equation (i), we get y = 2


By putting x = 2 in equation (i), we get y = 7


By putting x = 3 in equation (i), we get y = 12


A table is form such that :





Question 8.

Draw the graph of the equation,


Answer:

The given equation is y = 3x …….(i)


Now,


By putting x = 0 in equation (i), we get y = 0


By putting x = 1 in equation (i), we get y = 3


By putting x = 2 in equation (i), we get y = 6


By putting x = 3 in equation (i), we get y = 9


A table is form such that:





Question 9.

Draw the graph of the equation,


Answer:

The given equation is y = - x …….(i)


Now,


By putting x = -2 in equation (i), we get y = 2


By putting x = -1 in equation (i), we get y = 1


By putting x = 0 in equation (i), we get y = 0


By putting x = 1 in equation (i), we get y = -1


A table is form such that:






Cce Questions
Question 1.

The point lies P (-5, 3) in
A. quadrant I

B. quadrant II

C. quadrant III

D. quadrant IV


Answer:

We can see that, x – coordinate is negative and y- coordinate is positive.

Hence, it can be clearly said that P (-5,3) lies in the 2nd quadrant.


∴ Option B is correct


Question 2.

The point Q (4, -6) lies in
A. quadrant I

B. quadrant II

C. quadrant III

D. quadrant IV


Answer:

We can see that, x – coordinate is positive and y- coordinate is negative.

Hence, it can be clearly said that Q (4,-6) lies in the 4th quadrant.


∴ Option D is correct.


Question 3.

The point Q (0, -4) lies
A. quadrant II

B. quadrant IV

C. on the x-axis

D. on the y-axis


Answer:

We can see that, x – coordinate is zero and y- coordinate is negative.

Hence, it can be clearly said that Q (0,-4) lies on the y axis.


∴ Option D is correct.


Question 4.

The point B (8, 0) lies
A. quadrant I

B. quadrant IV

C. on the x-axis

D. on the y-axis


Answer:

We can see that, x – coordinate is positive and y- coordinate is zero.

Hence, it can be clearly said that B (8,0) lies on the x axis.


∴ Option C is correct.


Question 5.

The point C(-6, 0) lies
A. quadrant II

B. quadrant III

C. on the x-axis

D. on the y-axis


Answer:

We can see that, x – coordinate is negative and y- coordinate is zero.

Hence, it can be clearly said that C(-6,0) lies on the x axis.


∴ Option C is correct.


Question 6.

The point at which the two coordinate axes meet is called
A. the abscissa

B. the ordinate

C. the origin

D. the quadrant


Answer:

Origin is the point of intersection of the two coordinate axes.

∴ Option C is correct.


Question 7.

If x > 0 and y < 0, then the point (x, y) lies in
A. quadrant I

B. quadrant II

C. quadrant III

D. quadrant IV


Answer:

We have, x > 0 and y < 0

∴x is positive and y is negative


= point (x, -y) lies in 4th quadrant


∴ Option D is correct.


Question 8.

The points (other than the origin) for which the abscissa is equal to the ordinate lie in
A. quadrant I only

B. quadrant I and II

C. quadrant I and III

D. quadrant II and IV


Answer:

We know that abscissa and ordinate can be equal in only two cases i.e.

i. x and y both are positive


ii. x and y both are negative


∴The points will lie in the 1st and 3rd quadrants only.


∴ Option C is correct.


Question 9.

The point in which abscissa and ordinate have different signs will the in
A. quadrant I and II

B. quadrant I and IV

C. quadrant IV and II

D. quadrant II only


Answer:

We know that abscissa and ordinate can have different signs in only two cases i.e.

i. x is negative and y is positive


ii. x is positive and y is negative


∴The points will lie in the 2nd and 4th quadrants only.


∴ Option C is correct.


Question 10.

The perpendicular distance of the point A (7, 5) from y-axis is
A. 7 units

B. 5 units

C. 12 units

D. 2 units


Answer:

Since, we have the point A (7, 5)

And we have to find its perpendicular distance from y-axis


∴The perpendicular distance will be the x- coordinate


Hence, it is 7 units.


∴ Option A if correct.


Question 11.

A point both of whose coordinates are negative lies in
A. quadrant I

B. quadrant II

C. quadrant III

D. quadrant IV


Answer:

We have, both the coordinates are negative i.e.

x and y both are negative


Hence, the point lies in the 3rd quadrant.


∴ Option C is correct


Question 12.

Abscissa of a point is positive in
A. quadrant I only

B. quadrant II only

C. quadrant I and II

D. quadrant I and IV


Answer:

We have, (x, y)

Where, x is positive


Hence it may lie in either 1st or 4th quadrant.


∴ Option D is correct.


Question 13.

The coordinates of two points are and then (abscissa of A) – (abscissa of B) = ?
A. 1

B. -1

C. 5

D. -5


Answer:

Here, abscissa of A = 3

Abscissa of B = -2


According to the question,


(abscissa of A) – (abscissa of B) = 3 – (-2)


= 3 + 2 = 5


∴ Option C is correct.


Question 14.

The points A(2, –2), B(3, – 3), C(4, – 4) and D(5, –5) all lie in
A. quadrant II

B. quadrant III

C. quadrant IV

D. different quadrants


Answer:

Let us see the plot of these points,



Since, all the given points have their x – coordinate positive and y – coordinate negative.

Hence, all these points lie in the 4th quadrant. And also they all lie in a straight line.


∴ Option C is correct


Question 15.

Which of the points A(0, 6), B(–2, 0), C(0, – 5) D(3, 0) and E(1, 2) does not lie on x-axis?
A. A and C

B. B and D

C. A, C and E

D. E only


Answer:

We know that, a point can only lie on x-axis if its y coordinate is 0.

Hence, points A, C and E does not lie on x-axis


∴ Option C is correct


Question 16.

The signs of abscissa and ordinate of a point in quadrant II are respectively
A. (+, -)

B. (-, +)

C. (-, -)

D. (+, +)


Answer:

Since, in the 2nd quadrant x is negative and y is positive

Hence, as per sign the point could be written as (-, +)


∴ Option B is correct.


Question 17.

Which of the following points does not lie on the line y = 3x + 4?
A. (1, 7)

B. (2, 10)

C. (-1, 1)

D. (4, 12)


Answer:

We have,

y = 3x + 4 (i)


a. (1, 7) [putting x = 1 and y = 7 in (i)]


7 = 3(1) + 4


7 = 7


Thus, A lies on the line.


b. (2, 10) [putting x = 2 and y = 10 in (i)]


10 = 3(2) + 4


10 = 10


Thus, B lies on the line.


c. (-1, 1) [putting x = -1 and y = 1 in (i)]


1 = 3(-1) + 4


1 = 1


Thus, C lie on the line.


d. (4, 12) [putting x = 4 and y = 12 in (i)]


12 = 3(4) + 4


12 ≠ 16


Thus, D does not lie on the line.


∴ Option D is correct


Question 18.

Which of the following points lies on the line y = 2x + 3?
A. (2, 8)

B. (3, 9)

C. (4, 12)

D. (5, 15)


Answer:

We have, y = 2x + 3 (i)

a. (2, 8) [putting x = 2 and y = 8 in (i)]


8 = 2(2) + 3


8 ≠ 7


Thus, A doesn’t lie on the line.


b. (3, 9) [putting x = 3 and y = 9 in (i)]


9 = 2(3) + 3


9 = 9


Thus, B lies on the line.


∴ Option B is correct.


Question 19.

If a < 0 and b < 0, then the point P(a, b) lies in
A. quadrant IV

B. quadrant II

C. quadrant III

D. quadrant I


Answer:

We have, a < 0 and b < 0

i.e. both x and y are negative


Hence, point P lies in 3rd quadrant


∴ Option C is correct.


Question 20.

The perpendicular distance of the point P(4, 3) from the y-axis is
A. 3 units

B. 4 units

C. 5 units

D. 7 units


Answer:

Since, we have the point P (4, 3)

And we have to find its perpendicular distance from y-axis


∴The perpendicular distance will be the x- coordinate


Hence, it is 4 units.


∴ Option B is correct


Question 21.

The area of the ΔOAB with O(0, 0), A(4, 0) and B(0, 6) is
A. 8 sq units

B. 12 sq units

C. 16 sq units

D. 24 sq units


Answer:

Here, OA = 4 – 0 = 4 units

OB = 6 – 0 = 6 units





= 12 sq. units


∴ Option B is correct.


Question 22.

The area of the ΔOPQ with O(0, 0), P(1, 0) and Q(0, 1) is
A. 1 sq unit

B. sq unit

C. sq unit

D. 2 sq units


Answer:

Here, OA = 4 – 0 = 4 units

OB = 6 – 0 = 6 units





= 12 sq. units


∴ Option B is correct


Question 23.

Consider the three statements given below:

I. Any point on x-axis is of the form

II. Any point on y-axis is of the form

III. The point lies on both the axes.

Which is true?
A. I and II

B. I and III

C. II and III

D. III only


Answer:

Here,

1st statement is true as the point lying on x axis has its y coordinate as 0


2nd statement is true as the point lying on y axis has its x coordinate as 0


3rd statement is false as a point can never lie on both the axes unless it is their point of intersection i.e. (0, 0)


∴ Option A is correct


Question 24.

The question consists of two statements, namely, Assertion (A) and Reason (R). Please select the correct answer.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).

B. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).

C. Assertion (A) is true and Reason (R) is false.

D. Assertion (A) is false and Reason (R) is true.


Answer:

We have, pb(-3, 0)

Since, the y coordinate is 0.


Hence, it lies on x-axis.


∴ Option (a) is correct.


Question 25.

The question consists of two statements, namely, Assertion (A) and Reason (R). Please select the correct answer.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).

B. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).

C. Assertion (A) is true and Reason (R) is false.

D. Assertion (A) is false and Reason (R) is true.


Answer:

We have,

Point O(0, 0)


It does not lie in any of the quadrant because it is the point of intersection of both the axes.


∴ Option (d) is the correct option.


Question 26.

The question consists of two statements, namely, Assertion (A) and Reason (R). Please select the correct answer.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).

B. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).

C. Assertion (A) is true and Reason (R) is false.

D. Assertion (A) is false and Reason (R) is true.


Answer:

We know that,

The point P (-6, -4) lies in the third quadrant as the points of the type (-, -) lie in III quadrant


Also, we know that


The signs of points in quadrants I, II, III and IV are respectively (+,+) (-,+) (-,-) and (+,-)


∴ Both assertion and reason are true and reason justifies the assertion


Hence, option (a) is correct


Question 27.

The question consists of two statements, namely, Assertion (A) and Reason (R). Please select the correct answer.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).

B. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).

C. Assertion (A) is true and Reason (R) is false.

D. Assertion (A) is false and Reason (R) is true.


Answer:

According to question,

If a b then (a, b) (b, a)


This statement is true


Also, (4, -3) lies in the quadrant IV


As both assertion and reason are true but the reason does not justify the assertion


Hence, option (b) is correct


Question 28.

Write whether the following statements are true or false?

(i) The point lies in the quadrant I.

(ii) The perpendicular distance of the point from x-axis is 5 units.


Answer:

(i) The given statement is false as the ordinate of the point P (6, 0) is 0 and hence it lies on the x-axis

(ii) The given statement is also false because the perpendicular distance of the point A (5, 4) from the x-axis will be 4 units instead of 5 units



Question 29.

State whether true or false:

(i) The mirror image of the point in the x-axis is

(ii) The mirror image of the point in the y-axis is


Answer:

(i) The given statement is false because the mirror image of the point A (4, 5) on the x-axis is A’ (4, 5) instead of A’ (-4, 5)

(ii) The given statement is true as the mirror image of the point A (4, 5) in the y-axis is A’ (-4, 5)



Question 30.

Write whether the following statements are true or false:

A. The point (-5, 0) lies on x-axis.

B. The point (0, -3) lies in quadrant II.


Answer:

A. The given statement is true as the ordinate of the point is 0 which lies on the x-axis

B. The given statement is false as the point (0, -3) lies on the y-axis



Question 31.

Match the following columns:


The correct answer is:

A. -…….., B. -…….,

C. -…….., D. -…….,


Answer:

(a) We know that,

The points that lie on the x-axis have coordinate = 0


∴ The equation of the x-axis will be y = 0


(b) We know that,


The points that lie on the y-axis have abscissa = 0


∴ The equation of the y-axis will be x = 0


(c) We know that,


Any point on the x-axis is of the form (a, 0)


(d) We also know that,


A point on the y-axis is of the form = (0, b)


Hence the correct match for the given table is as follows:


(a) – (q)


(b) – (s)


(c) - (p)


(d) – (r)



Question 32.

Match the following columns:


The correct answer is:

A. -…….., B. -…….,

C. -…….., D. -…….,


Answer:

(a) We know that,

The point of the type (a, 0) lies on the x-axis


∴ Point A (-3, 0) lies on the x-axis


(b) We know that,


The point of the type (-, -) lie in the III quadrant


∴ Point B (-5, -1) lies in the quadrant III


(c) We know that,


The point of the type (+, -) lie in the quadrant IV


∴ Point C (2, -3) lies in the quadrant IV


(d) We know that,


The point of the type (o, b) lies on the y-axis


∴ Point D (0, -6) lies on the y-axis


Hence, the correct match for the above given table is as follows:


(a) - (s)


(b) – (r)


(c) – (q)


(d) – (p)



Question 33.

Without plotting the given points on a graph paper indicate the quadrants in which they lie, if

A) ordinate = 6, abscissa = - 3

B) ordinate = 6, abscissa = 4

C) abscissa = -5, ordinate = -7

D) ordinate = 3, abscissa = 5


Answer:

A. We know that,

Point (-3, 6) lie in the second quadrant


B. We know that,


Point (4, -6) lie in the fourth quadrant


C. We know that,


Point (-5, -7) lie in the third quadrant


D. We know that,


Point (5, 3) lie in the first quadrant



Question 34.

Plot the point P(–6, 6) on a graph paper. Draw PL ⊥ x-axis and PM ⊥ y-axis. Write the coordinates of L and M.


Answer:

The required point is shown in the graph given below:


In the above graph PL is drawn perpendicular to x-axis while PM is drawn perpendicular to y-axis


∴ Coordinates of L = (-6, 0)


Also, coordinates of M = (0, 3)



Question 35.

Plot the points A(–5, 2), B(3, –2), C(–4, –3) and D(6, 0) on a graph paper.


Answer:

The given four points A (-5, 2), B (3, -2), C (-4, -3) and D (6, 0) are plotted on the graph paper as follows:



Question 36.

The three vertices of ΔABC are A(1, 4), B(–2, 2) and C(3, 2). Plot these points on a graph paper and calculate the area of ΔABC.


Answer:

Let the vertices of the triangle be A (1, 4), B (-2, 2) and C (3, 2)


Now, when we plot and join these points on the graph paper, we get a triangle ABC


Let the line BC intersect y-axis at D


∴ BC = BD + DC


= (2 + 3) units


= 5 units


Now, AL is drawn perpendicular to x-axis meeting BC at L


∴ Ordinate of point L = Ordinate of point C – 2


AL = AM – LM


= 4 – 2


= 2 units


Hence, area of =


=


=


= 5 units


∴ Area of the triangle ABC = 5 square units



Question 37.

The three vertices of a rectangle ABCD are A(2, 2), B(–3, 2) and C(–3, 5). Plot these points on a graph paper and find the coordinates of D. Also, find the area of rectangle ABCD.


Answer:

Let the three vertices of rectangle ABCD be A (2, 2), B (-3, 2) and C (-3, 5)

Now, on plotting these points on the graph paper and by joining the points we get:



The point A lies in the first quadrant while B and C lie in the second quadrant


Let us assume D be the fourth vertex of the rectangle


∴ Abscissa of D = Abscissa of A = 2


And, Ordinate of D = Ordinate of C = 3


Hence, Coordinate of the fourth vertex, D = (2, 5)


Let y-axis cut AB and CD at point L and M respectively


∴ AB = (BL + LA)


= (3 + 2)


= 5 units


Also, BC = 5 – 2


= 3 units


∴ Area of rectangle ABCD = BC × AB


= 3 × 5


= 15 square units


Hence, the area of the rectangle ABCD is 15 square units



Question 38.

The three vertices of a rectangle ABCD are A(3, 2), B(–2, 2) and C(3, –3). Plot these points on a graph paper and find the coordinates of D. Also, find the area of rectangle ABCD.


Answer:

Let the three vertices of rectangle ABCD be A (3, 2), B (-2, 2) and D (3, -3)

Now, on plotting these points on the graph paper and by joining the points we get:



A, B and D lie in different quadrants


Let us assume D be the fourth vertex of the rectangle


∴ Abscissa of C = Abscissa of B = - 2


And, Ordinate of C = Ordinate of D = - 3


Hence, Coordinate of the fourth vertex, C = (-2, -3)


Let y-axis cut AB and CD at point L and M respectively


∴ AB = (BL + LA)


= (2 + 3)


= 5 units


∴ Area of rectangle ABCD = AB × AB


= 5 × 5


= 25 square units


Hence, the area of the rectangle ABCD is 25 square units



Question 39.

From the figure given below write each of the following:



(i) The coordinates of point D

(ii) The abscissa of the point A

(iii) The point whose coordinates are (2,-3)

(iv) The point whose coordinates are (-3,-4)

(v) The ordinate of point E

(vi) The coordinates of B

(vii)The coordinates of F

(viii)The coordinates of the origin


Answer:

(i) We have,

Abscissa of point D = 0


Ordinate of point D = -5


∴ Coordinates of point D = (0, -5)


(ii) From the given graph, we have:


Abscissa of point A = - 4


(iii) From the given graph, we have:


Coordinates of point E = (2, -3)


(iv) From the given graph, we have:


Coordinates of point C = (-3, -4)


(v) From the given graph, we have:


Ordinate of point E = - 3


(vi) From the given graph, we have:


Point B lies on x-axis


∴ Abscissa of point B = - 2


Ordinate of point B = 0


Hence coordinates of point B are (-2, 0)


(vii) From the given graph, we have:


Abscissa of point F = 5


Ordinate of point F = - 1


(viii) From the given graph, we have:


Coordinates of the origin = (0, 0)




Formative Assessment (unit Test)
Question 1.

If x < 0 and y > 0, then the point (x, y) lies in
A. quadrant I

B. quadrant II

C. quadrant III

D. quadrant IV


Answer:

According to question, we have

x < 0 and y > 0 then these points will lie in second quadrant


As, points of the type (-, +) lie on the second quadrant


∴ Option B is correct


Question 2.

Which point does not lie in any quadrant?
A. (3, -6)

B. (-3, 4)

C. (5, 7)

D. (0, 3)


Answer:

From the given options in the question the point which does not lie in any quadrant is (0, 3)

∴ Option D is correct


Question 3.

The area of ΔAOB having vertices A( 0,6) , O( 0,0) and B( 6,0) is
A. 12 sq units

B. 36 sq units

C. 18 sq units

D. 24 sq units


Answer:

When we plot the given points in the graph paper then,

is the right angle triangle, where


OB = Base = 6 units


Height of triangle = OA = 6 units


∴ Area of =


=


=


= 18 square units


∴ Option C is correct


Question 4.

Read the statements given below and choose the correct answer:

I. Any point on x-axis is of the form for all

II. Any point on y-axis is of the form for all

III. Any point on both the axes is of the form for all and

Which of the following is true?
A. I and II

B. I and III

C. I only

D. III only


Answer:

We know that,

Any point which lies on the x-axis is of the form (x, 0) for x


Also, point which lies on the y-axis is of the form (0, y) for y


Hence, statement I and II are true


∴ Option A is correct


Question 5.

Which of the following points does not lie on the line 3y = 2x – 5?
A. (7, 3)

B. (1, -1)

C. (-2, -3)

D. (-5, 5)


Answer:

From the given four options, (-5, 5) does not satisfy the given equation:

3x = 2x – 5


We have,


R.H.S = 2 × (-5) – 5


= - 10 – 5


= - 15


Also, L.H.S = 3 × 5


= 15


Hence, the point (-5, 5) does not lie on the line 3y = 2x – 5


∴ Option D is correct


Question 6.

Plot each of the following points on a graph paper:

A(3, –5), B(–5, –2), C(–6, 1) and D(4, 0).


Answer:

The following given points are plotted on the graph paper as follows:



Question 7.

If 2y = 3 – 5x, find the value of y when x = –1.


Answer:

We have,

2y = 3 – 5x


Now, by putting the value of x = - 1 in the given equation we get:


2y = 3 – 5 × (-1)


2y = 3 + 5


2y = 8


y = = 4


Hence, when x = - 1 then y = 4



Question 8.

On which axis does the point A(0, –4) lie?


Answer:

We have,

Abscissa of point A (0, -4) = 0


∴ Point A lies on the y-axis



Question 9.

In which quadrant does the point B(–3, –5) lie?


Answer:

From the given point given in the question, we have

The abscissa and the ordinate of the point B (-3, -5) are negative and we know that those points lie on the III quadrant


∴ Point B lies in the third quadrant



Question 10.

What is the perpendicular distance of the point P(–2, –3) from the y-axis?


Answer:

We have,

Abscissa of point P (-2, -3) = - 2


We know that, distance cannot be negative


∴ The perpendicular distance of the given point from the y-axis is 2 units



Question 11.

At what point do the coordinate axes meet?


Answer:

The coordinate axes meet at the origin i.e., at point O (0, 0)



Question 12.

For each of the following write true or false:

(i) The point lies in quadrant I.

(ii) The ordinate of a point is -3 and its abscissa is -4. The point is

(iii) The points and both lie in quadrant IV.

(iv) A point lies on y-axis at a distance of 3 units from x-axis. Its coordinates are (3, 0).

(v) The point lies on y-axis.

(vi) The point lies on x-axis as well as y-axis.


Answer:

(i) The given statement is false as the given point lies on the x-axis

(ii) The given statement is also false as the point is P (-4, -3)


(iii) The given statement is also false as the point A (1, -1) lies in the quadrant IV and point B (-1, 1) lies in the quadrant II


(iv) The given statement is false as the coordinates of the point are (0, 3)


(v) The given statement is true as the point C (0, -5) lies on y-axis


(vi) The given statement is also true as the point O (0, 0) lies on x-axis as well as y-axis



Question 13.

Taking a suitable scale, plot the following points on a graph paper:


Answer:

The concept is:

(+x, +y) 1st Quadrant


(-x, +y) 2nd Quadrant


(-x, -y) 3rd Quadrant


(+x, -y) 4th Quadrant


The given points are plotted as follows:




Question 14.

Read the graph paper given below and answer the following:

(i) Write the points whose ordinate is 0.

(ii) Write the points whose abscissa is 0.

(iii) Write the points whose ordinate is -3.

(iv) Write the points whose abscissa is 2.

(v) Write the coordinates of all points in quadrant II.

(vi) Write the coordinates of all those points for which abscissa and ordinate have the same value.



Answer:

(i)The given four points G (-3, 0) , H (-8, 0), Q (4, 0) and R (9, 0) lie on the x-axis

∴ Their ordinates are equal to O


(ii) The given four points L (0, -6) , K (0, -2), D (0, 3) and C (0, 7) lie on the x-axis


∴ Their abscissa are equal to O


(iii) The ordinates of points M (-1, 3) , J (-4, -3) and P (6, 3) are equal to -3


(iv) Points having abscissa equal to 2 is B (2, 4) and N (2, -1)


(v) From the given points, points E and F lie in quadrant II


∴ Coordinates of E = (-4, 4)


Coordinates of F = (-6, 2)


(vi) Coordinates of all those points having abscissa and ordinate same value are:


A (3, 3) and I (-2, -2)



Question 15.

(i) Write the mirror image of the point
(2, 5) in the x-axis.

(ii) Write the mirror image of the point
(3, 6) in the y-axis.

(iii) A point (a, b) lies in quadrant II. In which quadrant does (b, a) lie?


Answer:

(i) The mirror image of the point (2, 5) in the x-axis is (2, -5)

(ii) The mirror image of the point (3, 6) in the y-axis is (-3, 6)


(iii) According to question,


Point (a, b) lies in the second quadrant so a must be a negative number and b must be a positive number


∴ Point (b, a) lies in the fourth quadrant



Question 16.

Without plotting the points on a graph paper indicate the quadrant in which they lie:

(i) ordinate = 4, abscissa = - 3

(ii) ordinate = - 5, abscissa = 4

(iii) abscissa = -1, ordinate = -2

(iv) abscissa = -5, ordinate = 3

(v) abscissa = 2, ordinate = 1

(vi) abscissa = 7, ordinate = -4


Answer:

The concept is:


(+x, +y) 1st Quadrant


(-x, +y) 2nd Quadrant


(-x, -y) 3rd Quadrant


(+x, -y) 4th Quadrant


(i) Points having ordinate = 4 and abscissa = - 3 lies in the quadrant II


(ii) Points having ordinate = - 5 and abscissa = 4 lies in the quadrant IV


(iii) Points having ordinate = - 2 and abscissa = - 1 lies in the quadrant III


(iv) Points having ordinate = 3 and abscissa = - 5 lies in the quadrant II


(v) Points having ordinate = 1 and abscissa = 2 lies in the quadrant I


(vi) Points having ordinate = - 4 and abscissa = 7 lies in the quadrant IV



Question 17.

Which of the following points do not lie on x-axis?

(i) A(0, 6) (ii) B(2, 0)

(iii) C(0, –2) (iv) D(–6, 0)

(v) E(2, 1) (vi) F(0, 4)


Answer:

From the points given in the question, we have

Points B (2, 0) and D (6, 0) have their ordinates = 0


∴ They lie on the point x-axis


And the point whose ordinate is not equal to zero does not lie on the x-axis


∴ Points A, C, E and F do not lie on the x –axis



Question 18.

Three vertices of a rectangle ABCD are A(3, 1), B(–3, 1) and C(–3, 3). Plot these points on a graph paper and find the coordinates of the fourth vertex D.


Answer:

Let the three vertices of rectangle ABCD be A (3, 1), B (-3, 1) and C (-3, 3)


Now, on plotting these points on the graph paper and by joining the points we get:


A lies in thye first quadrant while B and C lie in the second quadrant


Let us assume D be the fourth vertex of the rectangle


∴ Abscissa of D = Abscissa of A = 3


And, Ordinate of D = Ordinate of C = 3


Hence, Coordinate of the fourth vertex, D = (3, 3)



Question 19.

Write the coordinates of vertices of a rectangle OABC, where O is the origin, length OA = 5 units lying along x-axis, breadth AB = 3 units and B lying in the fourth quadrant.


Answer:

It is given in the question that,


OABC is a rectangle where O is the origin and OA = 5 units along x-axis


Also, AB = 3 units and B lies in the fourth quadrant


Now, coordinates of origin, O = (0, 0)


As point A lies on the x-axis


∴ Coordinate of point A = (5, 0)


Also, point B lies in the fourth quadrant


So, coordinate of point B will be negative


As the given width AB = 3 units


∴ Coordinates of point B = (5, -3)


Also, point C and O lies on the same line


Thus, abscissa of C = abscissa of O = 0


Similarly, Point C and B lies on the same altitude


Hence, both points have equal altitude


∴ Coordinates of C = (0, -3)


Hence, the coordinates of the vertices of the given rectangle are:


O (0, 0), A (5, 0), B (5, -3) and C (0, -3)



Question 20.

Plot the points A(2, 5), B(–2, 2) and C(4, 2) on a graph paper. Join AB, BC and AC. Calculate the area of ΔABC.


Answer:

Let the three vertices of triangle ABC be:

A (2, 5), B (-2, 2) and C (4, 2)

Now, when we plot these points in the graph paper then we see that,

Point A and C lie in the quadrant I and point B lie in the II quadrant

Let the line BC intersect y-axis at point D

∴ BC = (BD + DC)

= (2 + 4) units

= 6 units

Now, we have to draw AM perpendicular to x-axis and intersect BC at L

∴ Ordinate of point L = Ordinate of point B - Ordinate of point C

AL = AM – LM

= 5 – 2

= 3 units

Hence, Area of triangle ABC =

=

=

= 9 square units

∴ Area of triangle ABC = 9 square units