2D shapes and their properties

problem

Ball Bearings

Age

16 to 18

Challenge level

2 out of 3

If a is the radius of the axle, b the radius of each ball-bearing, and c the radius of the hub, why does the number of ball bearings n determine the ratio c/a? Find a formula for c/a in terms of n.
problem

A Rational Search

Age

16 to 18

Challenge level

3 out of 3

Investigate constructible images which contain rational areas.
article
What's Inside/Outside/Under the Box?

This article describes investigations that offer opportunities for children to think differently, and pose their own questions, about shapes.
page
Lafayette

What mathematical words can be used to describe this floor covering? How many different shapes can you see inside this photograph?
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Watch Those Wheels

Have you ever noticed the patterns in car wheel trims? These questions will make you look at car wheels in a different way!
article
Let's Get Flexible With Geometry

In this article for primary teachers, Ems explores ways to develop mathematical flexibility through geometry.
article
Going Deeper: Achieving Greater Depth With Geometry

This article for Primary teachers outlines how providing opportunities to engage with increasingly complex problems, and to communicate thinking, can help learners 'go deeper' with geometry.
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From One Shape to Another

Read about David Hilbert who proved that any polygon could be cut up into a certain number of pieces that could be put back together to form any other polygon of equal area.