Answer:
x = 75
Step-by-step explanation:
The triangle has 2 congruent sides and is therefore isosceles with 2 congruent base angles, both of measure x
The sum of the 3 angles = 180° , that is
x + x + 30 = 180
2x + 30 = 180 ( subtract 30 from both sides )
2x = 150 ( divide both sides by 2 )
x = 75
