Problem: In triangle ABC, with AB=AC=3.6, a point D is taken on AB at a distance 1.2 from A. Point D is joined to point E in the prolongation of AC so that triangle AED is equal in area to triangle ABC. Then AE equals:
Answer Choices:
A. 4.8
B. 5.4
C. 7.2
D. 10.8
E. 12.6
Solution:
Let the altitude from B to AC be h. Then the altitude from D to AE is 31​h​. Let AE=xˉ. Then
21​⋅31​hx=21​h(3.6)∴x=10.8