Question

what is m∠bac? (not drawn to scale)

Explanation:

Step1: Recall inscribed - angle theorem

The measure of an inscribed angle is half the measure of its intercepted arc.

Step2: Identify the intercepted arc

The inscribed angle $\angle BAC$ intercepts arc $BC$, and the measure of arc $BC$ is $60^{\circ}$.

Step3: Calculate the measure of $\angle BAC$

By the inscribed - angle theorem, $m\angle BAC=\frac{1}{2}m\overset{\frown}{BC}$. Since $m\overset{\frown}{BC} = 60^{\circ}$, then $m\angle BAC=\frac{1}{2}\times60^{\circ}=30^{\circ}$.

Answer:

A. 30