If AB be the diameter of a semicircle, and CD, CE the tangents to it from any point C, and if AE, BD be joined meeting in F, then CF is perpendicular to AB.
Geometric art is a form of art based on the use and application of geometric figures. A geometric figure is any set or combination of points, lines, surfaces and solids.
A mobile app or mobile application software is a computer program designed to run on smartphones and tablet computers.
Original problem 652.