Italian MO 2017 P1
Source: Italian MO 2017 P1
May 6, 2017
geometryrectangle
Problem Statement
Let and be positive real numbers. Consider a regular hexagon of side , and build externally on its sides six rectangles of sides and . The new twelve vertices lie on a circle. Now repeat the same construction, but this time exchanging the roles of and ; namely; we start with a regular hexagon of side and we build externally on its sides six rectangles of sides and . The new twelve vertices lie on another circle.
Show that the two circles have the same radius.