Answer:
x = 45°
Step-by-step explanation:
the triangle has 2 congruent sides and is therefore isosceles with the base angles being congruent, both x
the sum of the 3 angles = 180° , then
x + x + 90° = 180° ( subtract 90° from both sides )
2x = 90° ( divide both sides by 2 )
x = 45°
