Question

Hi, its me again. Find angle AOB

Answer 1

∠ABC = 115∘

Explanation:

∠ABC = 1/2 ∠AOC

(Angle subtended by a chord on major area is half of that subtended on center)

∴ ∠ABC = 1/2 x 130 = 65

ABCD is a cyclic quadrilateral

Sum of opposite angles = 180∘

∴ ∠ABC + ∠AOC = 180∘

∠ABC + 65 = 180∘

∠ABC = 115∘

Answer 2

AOC=360-130 = 230

ABC= 230/2=115