Thread: SAT Prep

SAT problem solving practice test 01




10. In the figure above AD = 4, AB = 3 and CD = 9. What is the area of triangle AEC ?
A. 18
B. 13.5
C. 9
D. 4.5
E. 3


you can go to the site above for an image it would not paste into here and the program wouldnt allow me to add a photo saved from the site

the answer is 4.5 but i cannot for the life of me recall how to do this.

Triangles ABE and CDE are similar, which allows finding AE/ED and therefore AE and ED.

can you go into depth a little further I thought they were similar but still having trouble finding an answer

From similarity, AB / CD = AE / ED = 1 / 3. Since AE + ED = 4, it follows that AE = 1 and ED = 3. (Formally, ED = 3AE and you solve the equation AE + 3AE = 4.)