Geometry Formulas Explained (VIDEO!)
In a high school geometry course students are often given formulas for the lateral area of a cone, the volume of a cone, the volume of a sphere and the surface area of the sphere with little or no explanation as to where they come from. (“It’s calculus – you’ll learn about it later on.”)
Here are four videos explaining the origin of these four formulas. [Of course, the work on the sphere is due to Archimedes, ca 250 B.C.E.]
The third video is a bit tough, and might be hard to follow with ease, but all the goods are there. The work here does not require high powered mathematics and a high school student keen on understanding these formulas does find this material within reach.