Question

An equilateral triangle ABC is inscribed in a circle with centre O. The measures of ∠BOC is :

A. 30° 

B. 60° 

C. 90° 

D. 120°

Answer 1

Option : (D)

Given that,

O is the centre of circle. 

Triangle ABC is an equilateral triangle 

∠A = ∠B = ∠C = 60° 

We Know that, 

An angle subtended by an arc at the centre of the circle is double the angle subtended at any point on the circle. 

∠BOC = 2∠BAC 

∠BOC = 2∠A 

∠BOC = 120°