Answer:
Step-by-step explanation:
Inscribed angle of diameter is 90°
⇒ ∠ACB = 90°
In ΔACB,
∠A + ∠ B + ∠ACB = 180° {Angle sum property of triangle}
a + 4a + 90 = 180
5a + 90 = 180
5a = 180 - 90
5a = 90
a = 90 ÷ 5
a = 19 -----------(I)
In ΔCOB,
OC = OB {Radius}
⇒ΔCOB is an isosceles triangle.
c = 4a {angles opposite to equal angles are conguent}
c = 4*19 {From (I)}
c= 76
