National Institute of Standards and Technology (NIST)
International System of Units: Si Base Units
This is the definitive source for information on SI base units, derived units, squares, cubes, luminosity, field strength and flux density.
TeachEngineering
Teach Engineering: New Boxes From Old
Students find the volume and surface area of a rectangular box (e.g., a cereal box), and then figure out how to convert that box into a new, cubical box having the same volume as the original. As they construct the new, cube-shaped box...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Faq, Geometric Figures
This page brings you to a table of contents of three-dimensional figures. Selecting a figure will bring you to a page defining and illustrating the figure with applicable formulas listed.