Question

Given that AB = AC and $\angle$BOC = ${140}^{\circ }$ where O is the center of the circle. $\angle$ABC =?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

$\angle$BAC = ${70}^{\circ }$

Angle subtended by an arc at the centre is twice the angle subtended by it at any point.

Since, $\Delta$ ABC is isosceles, $\angle$ABC = $\angle$ACB = $\frac{{180}^{\circ }-{70}^{\circ }}{2}$

$\therefore$$\angle$ABC = ${55}^{\circ }$