A proof without words Nov 23, 2020 Via nRICH: A circle touches the lines OA extended, OB extended and AB where OA and OB are perpendicular. Show that the diameter of the circle is equal to the perimeter of the triangle. $\blacksquare$ A selection of other posts May 6, 2015 A great student question Jun 11, 2014 The Dreadful Truth About The Table of Joy May 29, 2013 Maths in the real world: flowerpot volumes Aug 3, 2012 Silly questions amnesty subscribe via RSS