You may also like

Set Square

A triangle PQR, right angled at P, slides on a horizontal floor with Q and R in contact with perpendicular walls. What is the locus of P?

Mach Attack

Have you got the Mach knack? Discover the mathematics behind exceeding the sound barrier.

Construct the Solar System

Make an accurate diagram of the solar system and explore the concept of a grand conjunction.

Five Circuits, Seven Spins

Age 16 to 18
Challenge Level

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.

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
Copyright © 1997 - 2021. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project.