Geometry Demonstrations

These Geometry Demonstrations show you visually several Geometry concepts like volume, surface area, and the Pythagorean Theorem. I find it helpful to visually see geometry formulas.

Volume of a Cone

In this video you will see how the volume of a cone is equal to 1/3 the volume of a cylinder of equal radius and height.

The ratio of the volume of a cone is 1 to 3 of the equal sized cylinder. You will see that I was able to pour three cones filled with water into one cylinder.

Volume of a Pyramid Demonstration

In this video you will see how the the volume of a pyramid is 1/3 the volume of a prism that has the same shaped base. If you fill up a pyramid with water it will take three pyramids to fill up one prism.

Surface Area of a Sphere and a Hemisphere

In this video you will see how the surface area of a sphere equals the area of the great circle of the sphere. I covered a sphere with foil, and then drew four circles with the same radius as the great circle of the sphere. I next unwrapped the sphere and placed the foil in the four circles. You will see the foils fits in four circles.

You may also enjoy a demo of the Pythagorean Theorem