We will show how to construct a
Pentagon (a regular 5-sided polygon) by means of *the golden section.*

First, we will prove that in a
pentagon the proportion between a diagonal and a side is equal to *the
golden section*.

__Proof:__

Second, we will show how to construct a

We need the following remark:

Given a square with side length
2:

Finally, we use the above construction to construct a pentagon with a given side length. It's up to you to explain and to validate the construction.

Webpage by: Preben M Henriksen