Answer:
x = 37.5
Explanation:
The easiest way to solve this is to realize that the bottom triangle is a an Isosceles triangle, with the upper angle being equal to 180 - 75 degrees. That gives us the number 105°
Because it's an Isosceles triangle, we can simply say that the bottom angles, including the one we want to calculate are equal and both add up 105 (again, because the angles in a triangle add up to 180, and we know the top one is 105).
That gives us:
(180 / 105) / 2
= 75 / 2
= 37.5