Students stand and may not touch each other in this activity. Each student selects two other students to be ‘points’ in their triangle. The aim is to make an equilateral triangle, where all the sides are equal. Students keep who they are thinking about a secret. When the teacher says now the students begin to move around and try to keep their triangle equilateral. The challenge comes when the students’ partners have different plans and move around to try to make their own triangle. When the teacher says ‘stop’ everyone needs to stand still and the teacher examines examples of triangles.

The next time the activity is done there could be an added element when the teacher says ‘stop’: the students have to guess if they were in triangles made by other students.