Question

In the following figure, the value of a is ______.

विकल्प

• 20°

• 15°

• 5°

• 10°

Answer 1

In the following figure, the value of a is 10°.

Explanation:

We have,

∠AOF = ∠COD  ...[Vertically opposite angles]

∴ ∠COD = 90°

Now, 40° + 90° + 5a = 180°  ...[Angles on a straight line BOE]

⇒ 5a + 130° = 180°

⇒ 5a = 180° – 130° = 50°

⇒ a = `50^circ/5` = 10°