Question

What is the measurement of the vertex angle of an isosceles triangle if one of its base angles measures 42 degree

Answer 1

Hello from MrBillDoesMath!

Answer:

96 degrees

Discussion:

The base angles of an isosceles triangle are equal and a triangle has 180 degrees. In our case this means that

42 + 42 + (measure of vertex angle) = 180

84 + (measure of vertex angle)  = 180 =>     (subtract 84 from both sides)

84 - 84 +  (measure of vertex angle)  = 180- 84 =>  

(measure of vertex angle)  = 180- 84  = 96

Thank you,

MrB