Question

In the diagram below, ab and bc are tangent to o. what is the measure of adc

Answer 1

The correct option is B. 252°

Explanation:

There are 360° in the circle.

So using the relation :

`\frac{\text{(arc ADC - arc AC)}}{2} = \angle ABC`

⇒ arc ADC - arc AC = 2 × ∠ABC

⇒ arc ADC - 108° = 2 × 72°

⇒ arc ADC - 108° = 144°

⇒ arc ADC = 144° + 108°

⇒ arc ADC = 252°

So, The measure of ∠ADC = 252°

Hence, The correct option is B. 252°