Copyright © University of Cambridge. All rights reserved.

## 'Triangles All Around' printed from http://nrich.maths.org/

You might like to have a look at

Nine-Pin Triangles before trying this problem.

How many different triangles can you draw on a circular pegboard
which has four equally spaced pegs?

What are the angles of each triangle?

If you have a six-peg circular pegboard, how many different
triangles are possible now?

What are their angles?

How many different triangles could you draw on an eight-peg
board?

Can you find the angles of each?

You may like to use the interactivity to try out your ideas.

Full Size
Version
This text is usually replaced by the Flash movie.

For printable sets of circle templates for use with this activity,
please see

Printable Resources page.

Many thanks to Geoff Faux who introduced us to
the merits of the 9 pin circular geo-board.

The boards, moulded in crystal clear ABS
that can be used on an OHP (185 cm in diameter), together with a
teacher's guide, are available from Geoff at Education
Initiatives