MathDB
Rational Geometry

Source: 2018 AIME II #7

March 23, 2018
ratiogeometrytrapezoid

Problem Statement

Triangle ABCABC has sides AB=9,BC=53,AB=9,BC = 5\sqrt{3}, and AC=12AC=12. Points A=P0,P1,P2,,P2450=BA=P_0, P_1, P_2, \dots, P_{2450} = B are on segment AB\overline{AB} with PkP_k between Pk1P_{k-1} and Pk+1P_{k+1} for k=1,2,,2449k=1,2,\dots,2449, and points A=Q0,Q1,Q2,,Q2450=CA=Q_0, Q_1, Q_2, \dots ,Q_{2450} = C for k=1,2,,2449k=1,2,\dots,2449. Furthermore, each segment PkQk,k=1,2,,2449\overline{P_kQ_k}, k=1,2,\dots,2449, is parallel to BC\overline{BC}. The segments cut the triangle into 24502450 regions, consisting of 24492449 trapezoids and 11 triangle. Each of the 24502450 regions have the same area. Find the number of segments PkQk,k=1,2,,2450\overline{P_kQ_k}, k=1,2 ,\dots,2450, that have rational length.