Given an arbitrary planar quadrilateral UTAH, place a square outwardly on each side, and connect the centers of opposite squares: M, O, N, and Y. Then van Aubel's theorem states that the two lines MO and NY are of equal length and cross at a right angle.
Continue reading at:
gogeometry.com/vanaubel.html
http://www.youtube.com/watch?v=V1lT__1OLu8
ReplyDelete