Question

The base angle of an isosceles triangle is 15° more than its vertical angle..find its angle

Answer 1

let the angles be A, B and C
vertical angle = A = 15 + B/C [ B=C ]
<A +<B +<C = 180°
<A + <B +<C = 180° [B=C ]
<A +2 <B = 180°
15° + <B + 2 <B = 180°
3 <B = 180° - 15°
3 <B = 165°
<B = 165°/3 = 55°
Ans. <A = 55°+15°= 70°
<B =<C = 55°