<?xml version="1.0" encoding="ISO-8859-1"?>
<mdoxml version="1.0"><br></br>
<div>Look at the equilateral
triangle rotating around the equilateral triangle. It produces a
flower with three petals whose perimeter is ...</div>

<p><mdo:flash height="250" width="300"><param value="/content/02/11/six3/triang_rot_triang.swf" name="movie" ></param><param value="6" name="flashplayerversion" ></param><param value="250" name="height" ></param><param value="300" name="width" ></param></mdo:flash></p>

<p>Now consider a flower made
by the triangle rotating about a square - what is the perimeter of
the petals now?</p>

<p><mdo:flash height="300" width="320"><param value="/content/02/11/six3/rot_triang_sq.swf" name="movie" ></param><param value="6" name="flashplayerversion" ></param><param value="300" name="height" ></param><param value="320" name="width" ></param></mdo:flash></p>

<p>What is the perimeter when
the centre of the flower is a regular pentagon, hexagon,
heptagon...?<br></br>
What can you say about the increase in perimeter as the number of
sides of the centre shape increases?<br></br>
Can you explain this increase?<br></br>
 <br></br>
What would be the perimeter of a flower whose centre is a regular
$100$-sided polygon with side length $r$?</p>

<span style="font-style: italic;">It may help to work in terms of $\pi$
throughout this problem.</span><br></br></mdoxml>