MathDB
midpoints of sides are vertices of square.

Source: TOT 385 1993 Autumn A J3 - Tournament of Towns

June 12, 2024
geometrysquaremidpoints

Problem Statement

Three angles of a non-convex, non-self-intersecting quadrilateral are equal to 4545 degrees (i.e. the last equals 225225 degrees). Prove that the midpoints of its sides are vertices of a square.
(V Proizvolov)