This morning I decided to demonstrate how to use a compass and straight rule to find the incenter of a triangle.
This is a relatively easy task, especially given this rather cool way of bisecting an angle.
To construct this diagram, simly draw out a triangle:
Draw two concentric circles on two vertices:
Join each alternate segment like so:
Draw a line that from the vertex through the intersection:
Where they meet is the incenter. (incentre for UK?!)
Then colour it in for a laugh: