R s aggarwal solutions mathematics class 9 Solutions for Chapter 7 lines and angles

Exercises in Chapter 7 lines and angles Grade 9

Lines And Angles Exercise 7A

Lines And Angles Exercise 7B

Lines And Angles Exercise 7C

Questions in Lines And Angles Exercise 7A

Define the following terms:

(i) Angle

(ii) Interior of an angle

(iii) Obtuse angle

(iv) Reflex angle

(v) Complementary angles

(vi) Supplementary angles

Find the complement of each of the following angles:

(i) 55

(ii) 16

(iii) 90

(iv) 2/3 of a right angle

Find the supplement of each of the following angles:

(i) 42

(ii) 90

(iii) 124

(iv) 3/5 of a right angle

Find the measure of an angle which is

(i) Equal to its complement

(ii) Equal to its supplement

Find the measure of an angle which is 36 more than its complement.

Find the angle which is four times its complement.

Find the angle which is five times its supplement.

Find the angle whose complement is one third of its supplement.

Questions in Lines And Angles Exercise 7B

In the adjoining figure, AOB is a straight line. Find the value of x.

In the adjoining figure, AOB is a straight line. Find the value of x. Hence, find ∠AOC, ∠COD and ∠BOD.

In the adjoining figure, what value of x will make AOB, a straight line?

Two lines AB and CD intersect each other at a point O such that ∠AOC: ∠AOD = 5:7. Find all the angles.

In the given figure, three lines AB, CD and EF intersect at a point O such that ∠AOE = 35 and ∠BOD = 40. Find the measure of ∠AOC, ∠BOF, ∠COF and ∠DOE.

Prove that the bisectors of two adjacent supplementary angles include a right angle.

Questions in Lines And Angles Exercise 7C

In the given figure, l || m and a transversal t cuts them. If ∠1 = 120o, find the measure of each of the remaining marked angles.

In the figure, l || m and a transversal t cuts them. If ∠7 = 80o, find the measure of each of the remaining marked angles.

In the figure, AB || CD and BC || ED. Find the value of x.

In the figure, AB || CD || EF. Find the value of x.

In the given figure, AB || CD. Find the values of x, y and z.

In the given figure, AB || CD. Find the value of x.

In the given figure, AB || PQ. Find the values of x and y.

In the given figure, AB || CD. Find the value of x, y and z.

In the given figure, AB || CD. Prove that p + q – r = 180.

In the given figure, AB || CD and EF || GH. Find the values of x, y, z and t.

In the given figure, AB || CD and a transversal t cuts them at E and F respectively. If EP and FQ are the bisectors of ∠AEF and ∠EFD respectively, prove that EP || FQ.