Answer:
x = 45
Step-by-step explanation:
In isosceles triangles (a triangle where two sides are equal), the two base angles are congruent.
The sum of angles in a triangle is 180°.
In this problem, x is a base angle, so the other base angle is equal to x.
So, adding up all the measures of the angles in this triangle,
90 + x + x = 180
Simplify.
2x + 90 = 180
Substract 90 from both sides
2x = 90
Divide both sides by 2
x = 45
