In Fig. 5.27, a = 40°. The value of b is
a. 20°
b. 24°
c. 36°
d. 120°

Solution:

Given, the figure represents a straight line and a ray produced from the line.

a = 40°

We have to find the value of b.

We know that the sum of a linear pair of angles is always equal to 180 degrees.

From the figure,

2a + 5b = 180°

2(40°) + 5b = 180°

80° + 5b = 180°

5b = 180° - 80°

5b = 100°

b = 100°/5

Therefore, b = 20°

✦ Try This: From the adjacent figure, find the value of x.

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 5

NCERT Exemplar Class 7 Maths Chapter 5 Problem 33

In Fig. 5.27, a = 40°. The value of b is: a. 20°, b. 24°, c. 36°, d. 120°

Summary:

In Fig. 5.27, a = 40°. The value of b is 20°

☛ Related Questions:

• If an angle is 60° less than two times of its supplement, then the greater angle is: a. 100°, b. 80° . . . .
• In Fig. 5.28, PQ || RS. If ∠1=(2a+b)° and ∠6=(3a-b)°, then the measure of ∠2 in terms of b is: a. (2 . . . .
• In Fig. 5.29, PQ||RS and a : b = 3 : 2. Then, f is equal to: a. 36°, b. 108°, c. 72°, d. 144°