MNOP is a cyclic quadrilateral. The angle bisector of ∠PMN and ∠PON meets the circle at point A and B respectively. Find the value of ∠AMB?
(a) 45°
(b) 90°
(c) 60°
(d) 120°
Sol:
Assume any angle ∠PMN = 60°
Angle made by arc BN = 60° at
So angle made by arc BN = 60° at M
∴ ∠AMB = 90°
