Question

What is the value of a,c ?

Answer 1

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