Formulas Explained: Area of Cone, Volume of Cone, Volume of Sphere

Formulas Explained: Area of Cone, Volume of Cone, Volume of Sphere
Formula for the Lateral Area of a Cone: Video I
In this first video of “geometry formulas explained” we explain why the lateral area of a cone is pi*radius*slant height. Such formulas are often given to geometry students with no explanation. Here’s an explanation!

Formula for the Volume of a Cone: Video II
In this second video of “geometry formulas explained” we explain why the volume of a cone is 1/3 the volume of the cylinder that surrounds it. This is a bit of a meaty video and will take some work to follow properly - but the goods are all there.

Formula for the Volume of a Sphere: Video III
In this third video of “geometry formulas explained” we show how Archimede’s deduced found the volume of a sphere. To do so he had to use a formula for the volume of a cone (which we derive in video II).

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