A builder was given a design plan for a triangular roof as shown. Explain how he knows that △AED ∼ △ACB. Then find AB.

Answer:
angle AED is congruent to angle ECB and angle ADE is congruent to angle DBC.
Triangle AED is congruent to triangle ACB
AB = 28 feet
Step-by-step explanation:
6/AB = 9/42
42(6) = 9AB
252=9AB
AB=28