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Calculator.net: Surface Area Calculator
Use these calculator tools to find the surface area, in your choice of units, of a sphere, cone, cube, cylinder, rectangular prism, capsule, ball cap, conical frustum, ellipsoid, or square pyramid. Includes a reference section listing...
University of Cambridge
University of Cambridge: Nrich: Making Boxes
Have fun and learn by making a box and then find out its maximum volume as well as other problem-solving activities, including making a table of your results and drawing a graph.