Question

the exterior angle at c of a triangle abc is equal to 120 degree. find the measure of all the angles of the triangle if angle a =angle b. what type of triangle is this​

Answer 1

Step-by-step explanation:

angle a = angle b= angle c = 60°

coz

angle c =180-120 =60°

angle a+b+c =360

a=b and c = 60°

on solving a= b=c=60°

Answer 2

Step-by-step explanation:

let the measure of angle a and angle b be x and measure of angle c be y

by exterior angle property of triangle

120° = x + x

120° = 2x

x = 120/2

x = 60°

Now, angle c and its exterior angle forms linear pair.

.•. 120 + y = 180 °

y = 180 - 120

y = 60°

In Δ ABC all angles are 60°. therefore it is equilateral triangle