1. BDC is a minor arc of a circle, centre O. CD is produced to E. If ∠BOC = 110°, find the number of degrees in ∠BDE. this is the diagram i came up with, http://img209.imageshack.us/img209/2500/circle4hm.jpg [Broken] by experimentation (i know it's weak), i found ∠BDE to be 55, exactly half of ∠BOC and i can't find a theorem to relate to this. anyone have ideas? thanks.