Posted by jenny on .
In triangle abc, point B is on segment ab, and point E is on segment bc such that segment de is parallel to segment ac if db=2, da=7, de=3, what is the length of segment ac?

geometrytypo 
MathMate,
"In triangle abc, point D is on segment ab,...."
If you draw the diagram according to the corrected information, you will find that triangles BDE and BAC are similar.
Since AC:DE = AB:DB, therefore
AC=AB*DE/DB=(7+2)*3/2=13.5