52. In the figure below, AB and AC are tangent to the circle at B and C, respectively, and O is the center of the circle. If ∠BAC measures 40°, how many degrees does ∠AOB measure?

Answer and Explanation

Your Answer is

Correct Answer is J

Explanation

According to the characteristics of tangents, it can be determined that AO is the angle bisector of angle BAC, and angle ABO is a right angle. Calculate the desired angle from the sum of the interior angles of a triangle and 180 degrees.