Fill in the blanks in Li's solution. . We were given the distance between the parallel lines, so both UW and Y V have a length of units. . AVUW and A WY V share a side, and we were given that this side is 10 units long. . Both AVUW and A WY V are right triangles, so we can use the Pythagorean theorem to find the lengths of VU and WY. . VU and WY both have a length of units. . AVUW ~ AWYV by the Side-Side-Side congruence postulate. . m/2 = since 21 and Z2 are corresponding parts of congruent triangles