Question

One of the base angle of an isosceles triangle is 80°. The vertical angle of the triangle isOne of the base angle of an isosceles triangle is 80°. The vertical angle of the triangle is

Answer 1

Answer:

20°

Step-by-step explanation:

in ∆ABC

AB=AC(equal sides of isosceles triangle)

base angle=angleABC=angleACB=80°(given)

angle ABC+ angle ACB + angleBAC= 180°(angle sum property of triangle)

angle BAC=180°-angle ABC- angle ACB

angle BAC=180°-80°-80°

angle BAC=180°-160°

angle BAC=20°

(angle BAC is vertical angle)