We first need to find the sum of the interior angles in a pentagon, which you do by doing (5 - 2) × 180, which equals 3 × 180 = 540°. Now you know that all of the angles inside the shape must add up to 540, so you can make an equation:
90 + 112 + 2x + 148 + 2x + 10 = 540
360 + 4x = 540
- 360
4x = 180
÷ 4
x = 45
I hope this helps!
