Five Circuits, Seven Spins

Stage: 5 Challenge Level: Challenge Level:2 Challenge Level:2

To find the dimensions of the tray you need to work out the angle through which the plate turns in one circuit and from that the length of its circumference that comes into contact with the edge of the tray as the plate rolls round.

 tray
You will need to use algebra to label the lengths of the side of the tray.

Published September 2000,March 2009,April 2009.