Provides formulas for problems involving trigonometry, circles, polygons, and general and linear equations. Includes properties of proportions, area and volume, triangle angle-bisector theorem, similarities in right triangles, ways to prove triangles are congruent, and ways to prove a quadrilateral is a parallelogram. Students can keep all the facts right at their fingertips with this colorful two-sided ready reference card! Comes pre-punched for a three-ring binder and is laminated for years of use. 8 1/2'' x 11'' (22 x 28cm).