The angle bisectors of angles A, B, and C meet its circumcircle at P, Q, and R. If ∠P = 72°, what is the value of ∠CAB?
Show answer & explanation
Correct answer: B
Explanation
When the angle bisectors of the triangle meet the circumcircle at P, Q, and R, then
in △PQR,
∠P = 90° − ∠A/2
∠P = 72°
72° = 90° − ∠A/2
∠A/2 = 18°
∠A = 36°
Therefore, ∠CAB = 36°