Equal Segments In An Isosceles Triangle Small 320×271 Medium 640×542 Large 1024×867 Download Tiff Original 2400×2033 | (387.3 KB) Description Illustration showing that if equal segments measured from the end of the base prolonged are laid off on the base of an isosceles triangle, the lines joining the vertex of the triangle to the ends of the segments will be equal. Keywords congruent angles, congruent segments, equal, geometric proof, isosceles triangle, prolonged base, triangles, Vertex Galleries Geometric Theorems and Proofs Source: C. A. Hart & Daniel D. Feldman Plane And Solid Geometry (New York: American Book Company, 1911) 32 Courtesy the private collection of Roy Winkelman