The Algebraic Pentagon - Dr Colin Wright

26th April 2025

Many people know how to use a compass and straight-edge to construct a regular hexagon, and by taking every other vertex we have a regular triangle. If you can construct a perpendicular bisector then you can get a square, and then double the number of sides of anything you've got so far.

If you look on the internet, you can find how to construct a regular pentagon and other shapes, but how do you know they are perfect?

In this talk, we'll visit the complex numbers and derive a practical construction for the regular pentagon. Or two.

Bring a compass to play along!