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 Mar 29, 2021 Why $\Gamma\left(\frac{1}{2}\right) = \sqrt{\pi}$ Apr 30, 2018 Eigenvalues Mar 4, 2015 Integrating $\sec^4(x)$ Apr 18, 2012 The insidious maths of payday loans (with added logarithms) subscribe via RSS