Question

In the given figure, ∠OAB = 110° and ∠BCD = 130° then ∠ABC is equal to

Answer 1

Step-by-step explanation:

ADC=

2

1

∠AOC

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

∴∠ADC=

2

1

×130=65

∘

Now, ADCB is cyclic quadrilateral ⇒

Sum of opposite Angles is 180

∘

∴∠ABC+∠ADC=180

∘

∠ABC+65=180

∘

∠ABC=115

∘