Skip over navigation
Guide and features
Guide and features
Science, Technology, Engineering and Mathematics
Featured Early Years Foundation Stage; US Kindergarten
Featured UK Key Stage 1&2; US Grades 1-4
Featured UK Key Stage 3-5; US Grades 5-12
Featured UK Key Stage 1, US Grade 1 & 2
Featured UK Key Stage 2; US Grade 3 & 4
Featured UK Key Stages 3 & 4; US Grade 5-10
Featured UK Key Stage 4 & 5; US Grade 11 & 12
This page contains a geoboard environment that can be used for circle work as well as well as other problems (such as
). There are also a number of problems that introduce circle theorems, all of which have a special version of the interactivity to support them. By working on the problems learners will develop a better understanding of some of the angle properties of circles.
A generic environment for supporting work on geometry and area can be found
Triangles in Circles
offers a good preparation for the problems
which lead towards the circle theorems.
Students will only need to know that the angles round a point add up to 360° and how to calculate angles in isosceles triangles.
"How many different triangles can you make which consist of the centre point and two of the points on the edge? Can you work out each of their angles?"
"What is the relationship between the angle at the centre and the angles at the circumference, for angles which stand on the same arc? Can you prove it?
focusses on the angle subtended by a semicircle.
"Can you make a right-angled triangle on this peg-board by joining up three points round the edge?What do you notice and can you explain it?"
"Make five different quadrilaterals on a nine-point pegboard, without using the centre peg. Work out the angles in each quadrilateral you make. Now, what other relationships you can see?"
Meet the team
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. More information on many of our other activities can be found here.
Register for our mailing list
Copyright © 1997 - 2014. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the
Millennium Mathematics Project