Triangle inscribed on circle proof I am missing something

[sjrrkb]

Triangle inscribed on circle proof...I am missing something :(

Homework Statement

I have provided a link to the problem below
http://imageshack.us/a/img854/4143/photo1lsd.jpg

I need to prove AE is an altitude on this proof

Homework Equations

all radii are congruent, cpctc, ASA, congruent supplementary angles are right angles

The Attempt at a Solution

I know that I need to draw in lines OB and OC for use in similar triangles and that once congruence is proven I can quickly show the supplementary angles are congruent and thus AE is an altitude.. I feel like this needs additional information saying E is the midpoint of BC...hence me being stuck. Any help would be appreciated.

 

[HallsofIvy]

Do you know, or can you prove, that any perpendicular bisector of a secant to a circle goes through the center of the circle?