MultimediaMultimedia Entries that feature multimedia: QuickTime movies, LiveGraphics3D, and JavaSketchpad. Angle Bisector Centroid Congruent Cube Dodecahedron Eccentricity Ellipse Equation of a Line Focal Radius Horizontal Line Equation Icosahedron Octahedron Orthocenter Plane Platonic Solids Point-Slope Equation of a Line Rectangular Parallelepiped Tautochrone Tetrahedron Vertical Line Equation Volume by Parallel Cross Sections