In the given figure ∠ AOC=130∘, The value of ∠ ABC (in degrees) is _______.
115º
115∘
50∘
100∘
115∘
Given ∠AOC = 130∘
.
Take a point P, anywhere on the circle. Join AP and CP.
Subtend ∠A0C at centre and ∠APC at remaining part of the circle.
∠APC = 12 ∠AOC = 12 ×130∘= 65∘
Again, ∠ABC + ∠APC = 180∘
∠ABC + 65∘ = 180∘
⇒∠ABC = 180∘- 65∘ =115∘