MathDB
Similar triangles involve centroid

Source: APMO 1991

March 11, 2006
trigonometrygeometry

Problem Statement

Let GG be the centroid of a triangle ABCABC, and MM be the midpoint of BCBC. Let XX be on ABAB and YY on ACAC such that the points XX, YY, and GG are collinear and XYXY and BCBC are parallel. Suppose that XCXC and GBGB intersect at QQ and YBYB and GCGC intersect at PP. Show that triangle MPQMPQ is similar to triangle ABCABC.