Answer:
C 70
Explanation:
since 2 sides are parallel to each other, so is then the third side, and their these are similar triangles. that means all angles of one triangle are the same in the other.
remember, the sum of all angles in a triangle is always 180 degrees.
so, we know 2 angles. one is 90 degrees, x is 20 degrees, therefore
y = 180 - 90 - 20 = 70