15)
∠EAD ≅ ∠CAB . . . . . . reflexive property. An angle is congruent with itself.
∠AED ≅ ∠ACB . . . . . . given
ΔABC ≅ ΔADE . . . . . . angle-angle similarity: If two angles are congruent, all three angles are congruent and the triangles are similar.