# 11/16: Group A: Induction (Olga Radko & Marisa Eisenberg);

Group B: Cyclic quadrilaterals (Po-Shen Loh)

Group A: We will take the first steps in learning the method of mathematical induction;

Group B: Any three non-collinear points always lie on some common circle, but in general it is rare for four points to have that property - unless one is trying to solve an Olympiad problem. Then, the observation that certain quadrilaterals are cyclic often turns out to be the key to the solution. We will survey some facts about cyclic quadrilaterals, and use them to solve actual Olympiad problems.