Sunday, September 21, 2025
– Live Presentation with
Colin Wright–
Session at 12 Noon Atlanta time
(check your time here)
Please join us starting 10 minutes before this session using the following button.
For published CoM presentations please visit the G4G YouTube channel
After this virtual CoM presentation on Zoom, we will meet for an informal social session in a different Zoom space where we can all see each other (see the blue button below). That Zoom meeting will start around 1pm ET.
Please join the social using the following button:
The Algebraic Pentagon
Most 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.
Have a compass to hand and play along!
