The figure below shows an arbelos ABC (AB, BC, and AC are semicircles of centers O1, O2,
and O) and the squares ABB1B2 and BCC1C2.
If M1 and M2 are the midpoints of B1B2
and C1C2, respectively, prove that AM2
and CM1 intersect at I, the incenter of the arbelos.
Typography of problem 1301