Parallelogram With Lines From opposite Vertices to Midpoints
Illustration to show that when lines from two opposite vertices of a parallelogram to the midpoints of the opposite sides are drawn, they trisect the diagonal.
Keywordsquadrilateral, quadrilaterals, diagonal, diagonals, parallelogram, angles, parallelograms, midpoint, midpoints, trisector, trisectors
G.A. Wentworth Plane And Solid Geometry (Boston: Ginn & Company, 1899) 72