In Fig. 5.13, POR is a line. The value of a is
a. 40°
b. 45°
c. 55°
d. 60°

Solution:

Given, POR is a line.

We need to find the value of a.

We know that the sum of angles on a straight line is always equal to 180 degrees.

So, ∠POQ + ∠ROQ = 180°

From the figure,

(3a + 5)° + (2a - 25)° = 180°

3a + 2a + 5° - 25° = 180°

5a + 20° = 180°

5a = 180° + 20°

5a = 200°

a = 200°/5°

a = 40°

Therefore, a = 40°

✦ Try This: From the given figure, find the value of the angle QPB.

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

NCERT Exemplar Class 7 Maths Chapter 5 Problem 13

In Fig. 5.13, POR is a line. The value of a is: a. 40°, b. 45°, c. 55°, d. 60°

Summary:

POR is a line. The value of a is 40°

☛ Related Questions:

• In Fig. 5.14, POQ is a line. If x = 30°, then ∠ QOR is: a. 90°, b. 30°, c. 150°, d. 60°
• The measure of an angle which is four times its supplement is: a. 36°, b. 144°, c. 16°, d. 64°
• In Fig. 5.15, the value of y is: a. 30°, b. 15°, c. 20°, d. 22.5°