Skip to content


Trigonometry is a branch of maths that relies on the relationships between the angles and sides of triangles.

This activity uses trigonometry to estimate the heights of tall objects, by making a simple tool that can measure angles.

A rolled up piece of paper with a protractor taped to the end, with string falling down across a protractor and a washer attached to the string.

Curriculum Links

Downloadable resources

SMG Learning Activities – How Tall Is That Tree (PDF Document)



Developed with the support of the Science Museum Group Academy’s Major Partner, MathWorks.