Question
82 of
100
Question Palette
Consider that O is the center of the circle and ∠APB = 50°. Then ∠OAB = ?
Correct Option:
B
Explanation
∠APB=50° is an angle at the circumference subtending chord AB. The central angle subtending the same chord is twice it:
∠AOB=2(50°)=100°.
Since OA=OB, triangle AOB is isosceles. Thus:
∠OAB=∠OBA
=(180°-100°)/(2)
=40°.
