Since segment xz is perpendicular to segment wy, angles wzx and xzy are both right angles and congruent. The proportion ________ shows the corresponding sides are proportional, so the triangles are similar by the sas similarity postulate. 5 over 10 equals 5 over 2 and one half 5 over 10 equals 5 over 5 10 over 5 equals 5 over 2 and one half 10 over 5 equals 2 and one half over 5.