Question

=

In the accompanying diagram of isosceles triangle ABC,
AB = BC, mZBAC = x, and mLABC = x + 30.
What is the value of x?
B
(x + 30)
A
The value of x is
The measure of the vertex angle is
degrees.

Answer 1

x = 50

Explanation:

The sum of interior angles in a triangle is equal to 180

Since triangle ABC is an isosceles triangle the measure of <c is also = x

x + x + x + 30 = 180 add like terms

3x + 30 = 180 subtract 30 from both sides

3x = 150 divide both sides by 3

x = 50