Answer:
By looking at the diagram, you can see what the measurements of a, b, and y.
m∠a = 90°
m∠b = 53.15°
m∠y = 36.87°
Since all triangles have a sum of 180° and the diagram shows a triangle, you will get 180° when you add up all of the measurements.
90 + 53.15 + 36.87 = 180.02
180.02 can be rounded to 180.