Question

A chord $RS$ subtends an angle of ${120}^o$ at the centre of the circle. What is the measure of the angle subtends chord $RS$ at any point on the circle.

Answer 1

By properties of circle, angle subtended by chord at centre of circle is twice to that subtended at any other point on circle $\Rightarrow$ RS subtended angle of ${60}^o$ on any other point on circle.