1. Here's proof that Pythagoras' theorem really works.
2. And here's a slightly longer explanation of why a² + b² = c².
3. This is how pi works.
4. This is why the area of a circle is πr².
5. This is how a straight line can draw out a curved shape.
6. Here are two more examples of straight lines tracing hyperboloids.
The one on the right shows the full hyperboloid.
7. Here's what tan(x) actually has to do with tangents.
8. Here's another way of looking at it.
9. This is how to construct a square using circles.
10. This is how to draw an ellipse with a piece of string.
11. This shows the relationship between sin(x) and cos(x).
12. This is how radians work.
13. This shows why angles in the same segment of a circle are equal.
14. This is how to make a fractal.
15. And this is how a fractal just keeps going forever.
16. And finally, how to draw a sumo wrestler using circles.
