In the given figure, 
is the center of the given circle and measure of arc 
is 100°. Determine 
and 
∠ADC = (1/2) ∠AOC
⇒ ∠ADC = (1/2) 100°
⇒ ∠ADC = 50°
Now,
∠ADC + ∠ABC = 180°[ABCD is a cyclic quadrilateral]
⇒ 50° + ∠ABC = 180°
⇒ ∠ABC = 130°
7
In the given figure, is the center of the given circle and measure of arc is 100°. Determine and
∠ADC = (1/2) ∠AOC
⇒ ∠ADC = (1/2) 100°
⇒ ∠ADC = 50°
Now,
∠ADC + ∠ABC = 180°[ABCD is a cyclic quadrilateral]
⇒ 50° + ∠ABC = 180°
⇒ ∠ABC = 130°