Question

Which of the following is the following measure of angle BOC

Answer 1

The tangent of a circle always form 90 degree angle with the radius. So measure of angle ABO and angle ACO is 90 degrees each.

The sum of angles of a quadilateral is 360 degrees. So,

$\angle BOC+\angle ABO+\angle ACO+\angle BAC=360$

Substitute the measures of angles in the equation to obtain the measure of angle BOC.

$\begin{gathered} \angle BOC+90+90+90=360 \\ \angle BOC=360-270 \\ =90 \end{gathered}$

Thus, measure of angle BOC is 90 degrees.