Midpoints of Triangle Divide Triangle into Four Equal Triangles Small 320×311 Medium 640×621 Large 1024×994 Download Tiff Original 2472×2400 | (275.0 KB) Description Illustration to show that if the lines joining the middle points of the sides of a triangle divide the triangle into four equal triangles. Keywords angle, angles, base, bisect, bisector, bisects, middle, midpoint, midpoints, side, Sides, triangle, triangles Galleries Miscellaneous Triangles Source: G.A. Wentworth Plane And Solid Geometry (Boston: Ginn & Company, 1899) 69 Courtesy the private collection of Roy Winkelman