Triangle inscribed on circle proof...I am missing something :( 1. The problem statement, all variables and given/known data I have provided a link to the problem below http://imageshack.us/a/img854/4143/photo1lsd.jpg [Broken] I need to prove AE is an altitude on this proof 2. Relevant equations all radii are congruent, cpctc, ASA, congruent supplementary angles are right angles 3. 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.