Question

if O is the centre
angle ( ODA - AOD )=15°
find angle ( ACB )??
​

Answer 1

Answer:

In given fig. O is centre of the circle if ∠AOC=130

o

 then find ∠ABC.

Step-by-step explanation:

Solution

∠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

∘