Geometry 2 DVD – This DVD begins where Geometry 1 leaves off. It's so easy and entertaining that the learning is almost effortless. Topics include: polygons, quadrilaterals, convex and concave regions, parallelograms, rhombuses (rhombi), trapezoids, similar triangles, altitudes, Pythagorean theorem, special right triangles, units and conversions, circles, circumference, the area congruence postulate, the area addition postulate, area formulas, surface area and volume formulas for right prisms, cylinders and spheres, and more. Total runtime is approximately 1 hour 5 minutes. Anyone can learn from this DVD—you will be pleased with this product.