# geometry

## Fermat’s Last Theorem

There are lots of Pythagorean triples; triples of whole numbers which satisfy:x2 + y2 = z2. But are there any which satisfyxn + yn =...

## Slices of Hanging Cubes

Hang a cube from one of its vertices. Now, if you slice it horizontally through its center, you get a...

## Koch Tetrahedron

In Koch Snowflake we saw an interesting fractal snowflake-like object that is obtained when gluing smaller triangles iteratively to the sides of...

## Hyperbolic Geometry

In the Fun Fact on Spherical Geometry, we saw an example of a space which is curved in such a way...

## Volume of a Ball in N Dimensions

The unit ball in Rn is defined as the set of points (x1,…,xn) such that x12 + … + xn2 <= 1. What...

## Sphere Eversions

If you take a loop of string in the plane and place an arrow along it pointing clockwise, is it...

If you’ve seen the Banach-Tarski paradox, you know that it is possible to cut a solid 3-dimensional ball into 5 pieces...

## Area of a Circle or Regular Polygon

There’s a nice way to see why the formula for the area of a circle of radius R is: Pi...