Question

an exterior angle of a triangle is 110° and two opposite angles are equal, find equal angles

Answer 1

As per the question , One angle whose exterior angle is given = 180-110 = 70°
Let the equal angles be x.
2x + 70 = 180
2x = 110
x= 55°
So, Equal angles are 55° each.

Answer 2

HELLO...

As we according to the exterior angle property that the exterior angle is = to the sum of its opposite angles

so let one angle be x and other be y 
thus, x+y=110

and here there is a condition given that both the opposite angles are =
so x=y
thus, we can write the equation as 
x+x=110
2x=110
x=110/2
x=55

thus the two equal angles measure 55

i hope this will help you......:)