Question

if an isosceles triangle angle at top vertex is twice the sum of base angle find all exterior angles of triangle

Answer 1

we know, in isosceles traingle , two sides are same , so two angles are also same .
let ∅ , ∅ and ¢ are the angle of isosceles triangle .

so, ∅ + ∅ + ¢ = 180°

a/c to question,

¢ = 2( ∅ + ∅ ) = 4∅

put this in above equation ,

∅ + ∅ + 4∅ = 180°

6∅ = 180°

∅ = 30°

and ¢ = 120°

hence , 30° , 30° and 120° are the angle of isosceles ∆