# #triangleABC# is isosceles, where AB=BC. If #m angleA= 5x+ 30# and #mangleB= 2x#, then how do you find #mangleC#?

##### 1 Answer

Dec 27, 2016

Please see the explanation.

#### Explanation:

Given:

I am going to use the notation where the side opposite the angle has the same letter but in lowercase. In this notation, AB becomes side c and BC becomes side a, therefore, AB = BC becomes c = a

Because c = a, we know that

Substitute the corresponding functions of x:

Solve for x: