500
A trapezoid has angles measuring 50, 50. Knowing that you need to know two angles, and knowing that a trapezoid has 360 degrees total, explain what the measure of the missing two angles must be.
What is 130 degrees each? If the two angles are both 50 degrees, then the other two angles must be equal as well. So, you could subtract 100 (50 + 50) from 360 and then divide that by the two angles you need. The answer you get is 130 degrees.