In the accompanying diagram of isosceles triangle ABC, AB = BC,m∠ BAC = x, and m∠ABC = x+30

Question

What is the value of x?

A. 80

B. 75

C. 50

D. 30

Answer 1

If I draw this out, it looks like BAC=BCA

The equation would be x+x+x+30=180 Combine like terms

3x+30=180 Subtract 30 from both sides

3x+30-30=180-30 Simplify

3x=150 Divide both sides by 3

3x/3=150/3 Simplify

x=50

Answer 2

The sum of the internal angles of a triangle is 180°.

x + (x+30°) + x = 180°

3x + 30° = 180°

3x = 150°

x = 50°

Answer 3

a+b+c=180

3x+30=180

3x=150

x=50°