These resources have been reviewed and selected by STEM Learning’s team of education specialists for factual accuracy and relevance to teaching STEM subjects in UK schools.

Circles in a Triangle

In this activity, students are presented with a series of different sized equilateral triangles each containing a number of circles, each of radius one unit. Students are required to find the exact area of each triangle.

The activity is extended into three dimensions by considering the volume of shapes packed with spheres.

Pythagoras' Theorem, trigonometry, surds, sequences and algebraic proof are needed for success in this task.

The formula for the nth term of a triangle number is needed from the start.

The resource includes a student hand out, teachers' notes and answers and is part of the collection of resources from Churchill Maths.

Show health and safety information

Please be aware that resources have been published on the website in the form that they were originally supplied. This means that procedures reflect general practice and standards applicable at the time resources were produced and cannot be assumed to be acceptable today. Website users are fully responsible for ensuring that any activity, including practical work, which they carry out is in accordance with current regulations related to health and safety and that an appropriate risk assessment has been carried out.


Show downloads

Information on the creators and permitted use of this resource is covered by the Category Three Materials - Community Resources section in STEM Learning’s Terms and conditions

Lists that tag this content