Answer:
x = 21
Step-by-step explanation:
Givens:
Every triangle's interior angles add up to 180°
The triangle has a right angle.
The triangle is isosceles (two equal sides and two equal angles)
Let's make an equation with the information we have already.
2 × (2x + 3) + 90 = 180
4x + 6 + 90 = 180
4x + 96 = 180
4x = 84
x = 21
