The figure shows a triangle ABC. Points D, E, F are chosen on AB, BC and AC, respectively, so that ADEF is a rhombus. Prove that the side of the rhombus is one-half the harmonic mean of AB and AC.
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 749.