Question

In the figure, given alongside, $AOB$ is a diameter of the circle and $\angle AOC={110}^o$. Find $\angle BDC$.

Answer 1

$\angle COB=180-110={70}^{\circ }$

$\angle BDC=\frac{70}{2}={35}^{\circ }$ (consider the arc BC)

In a circle, an arc subtends an angle at the center is twice the angle subtended by the same arc at any point of the remaining circle.