This lesson from Illuminations explores conic shapes. The shapes circle, ellipse, hyperbola, and parabola are illustrated. Students will discover how to cut a double-napped cone to create the various conic sections. The...

This lesson from Illuminations focuses on quadrilaterals. Students will start with the diagonals of a shape and then deduce the type of quadrilateral that surrounds them. An interactive applet is included that will help...

This lesson from Illuminations asks students to construct perpendicular bisectors, find circumcenters, calculate area, and use proportions to solve a real-world problem. Concepts taught in the lesson include...

This is a web site, created by Michael Frame, Benoit Mandelbrot, and Nial Neger of Yale University, to support a first course in fractal geometry for students without a strong mathematical background. It covers a wide...

This collection, created by Salman Khan of the Khan Academy, features videos on geometry. A basic understanding of Algebra I necessary to understand the fundamental elements featured in this collection. Altogether, the...