Answer:
90°
Step-by-step explanation:
There is no work. We know the right angle in the triangle and the x are supplementary. Meaning, they add up to 180 degrees. Therefore, 180-90 = 90. Think of it as a full triangle. If the 40 at the top was not half, but a full triangle, the 40 at the top would become 80. The 50 in the bottom left would mean there would be a 50 in the bottom right when you mirror the triangle. Therefore, you also need x to be 90 to make it a right triangle.
