Given AB = AC angle ABD = angle ACE to prove Triangle ACE = Triangle ABD.

In triangle ACE and ABD, angle A is common, by condition, angle ABD = ACE, side AB = AC, then triangles ACE is equal to triangle ABD along the side and two adjacent angles, which was required to be proved.

Then AD = AE = 15 cm, BD = EC = 10 cm, AB = AC = 7 cm.

Answer: AD = 15 cm, BD = 10 cm, AB = 7 cm.



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