In trying to replace the famous food pyramid, the U.S. Department of Agriculture has made a bold though risky decision. When USDA officials unveil their new food guidance program in the next few da… ...

Some 3D shapes, like cubes and pyramids, can be opened or unfolded along their edges to create a flat shape. The unfolded shape is called the net of the solid. Here are some 3D shapes and their nets.

"NASA Tests Shape-Shifting Robot Pyramid For Nanotech Swarms." ScienceDaily. ScienceDaily, 1 April 2005. <www.sciencedaily.com / releases / 2005 / 03 / 050331110135.htm>.