Question

If the base angles of an isosceles triangle measure 2x+2 and 4x-20, what is the value of x and the measure of the vertex angle?

Answer 1

i think x = 30 but im not sure so please dont quote me on this

Answer 2

x = 11 and vertex = 132°

the base angles of an isosceles triangle are equal, thus

4x - 20 = 2x + 2 ( subtract 2x from both sides )

2x - 20 = 2 ( add 20 to both sides )

2x = 22 ⇒ x = 11

base angles = ( 2 × 11) + 2 = 24°

vertex angle = 180° - ( 2 × 24 ) = 132°