Experiment with an orange


Hello, today i'm going to show you an experiment that you can use in your classes of geometry.

It shows the explanation, and why the area of the sphere is four times the area of the circle.

MATERIALS

- An orange
- A pen
- A paper

PROCESS

1. To start with it, you have to put the orange in the paper, and draw with the pen the maximum circle that the orange has. You have to do it four times (four circles).

2. Now you have to peel the orange, making the pieces the smallest you can.

3. The small pieces of the skin of the orange will be introduced in the circles, without any hole, as a puzzle.

4. In this way we can ensure that all the skin fits in the four circles.

EXPLANATION

With this experiments, you can show students that the area of the sphere is four times  the area of the circle, as the area of the circle is:


And the area of the sphere is four time of the previous one:


Here you have the video of the demonstration:




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