In the given figure, O is the centre of a circle. Then ∠OAB=?
(a) 50∘
(b) 60∘
(c) 55∘
(d) 65∘
Open in App
Solution
ANSWER: (d) 65° We have: OA = OB (Radii of a circle) Let ∠ OAB = ∠ OBA = x ° In Δ OAB, we have: x ° + x ° + 50° = 180° (Angle sum property of a triangle) ⇒ 2 x ° = (180° - 50°) = 130° ⇒ x=1302°=65° Hence, ∠OAB = 65°