MathDB
Star shape region with centers A, B => all of [AB] centers

Source: Bundeswettbewerb Mathematik 1973, round 1, problem 2

May 1, 2007
geometry proposedgeometry

Problem Statement

In a planar lake, every point can be reached by a straight line from the point AA. The same holds for the point BB. Show that this holds for every point on the segment [AB][AB], too.