Corresponding angles of similar polygons are congruent. We assume that two angles with given measures are corresponding angles.
4x + 10 = 80
4x = 70
x = 17.5
Answer: 17.5
Because the polygons are similar, the indicated angles are identical. Thus,
4x + 10 = 80, and 4x = 70, so that x = 17.5.
