Question

In the following figure, a = 40°. The value of b is ______.

पर्याय

• 20°

• 24°

• 36°

• 120°

Answer 1

In the folllowing figure, a = 40°. The value of b is 20°.

Explanation:

From the given figure it is clear that,

2a + 5b = 180°    ...[Linear pair]

⇒ 2 × 40° + 5b = 180°   ...[∵ a = 40°]

⇒ 80° + 5b = 180° 

⇒ 5b = 180° – 80° 

⇒ 5b = 100°

⇒ b = `100^circ/5`

∴ b = 20°