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Age Range: 5-7 | 7-11
Duration: 30-59 mins
  • Maths

Using Pythagoras Theorem

Discover how to use Pythagoras theorem to create a string triangle that can be used to measure everyday objects

In this engaging STEM activity for kids, students will be introduced to the concept of Pythagoras Theorem and what it is used for. The main activity involves making a string triangle in the proportion of 3:4:5 and using this to check whether objects are perpendicular to their base.

This activity is aimed at primary school children and could be used as a main lesson activity, to introduce Pythagoras Theorem or to teach learners about how the ancient Greeks have affected life in the modern world.

Activity introduction

This is one of a set of resources designed to allow learners to use practical methods to support the delivery of key topics within design and technology, maths, and history.

In this resource students will discover how to create a visual aid to measure objects using ancient Greek mathematics. They will make a string triangle and then use it to check if the object is perpendicular to its base – an application of Pythagoras.

Learners will work in pairs to make their string triangles using hammers, nails, string, and a piece of wood.

The teacher will then demonstrate how to measure the perpendicular nature of objects – if the hypotenuse is straight, then the object is perpendicular.

Finally, students will complete a worksheet in pairs, looking at a variety of objects and judging if they are perpendicular or not.

A free activity sheet is provided.

What you will need

  • 2 nails (finishing type, 60 mm plus long)
  • Ruler and pencil, for marking out
  • Hammer
  • Smooth piece of wood
  • String/ribbon 70cm long
  • Tape
  • Sheet of clear plastic (for extension)

The Ancient Greeks connection

This activity is inspired by the achievements of ancient Greece. The ancient Greeks influenced the modern world in many ways and made important contributions to the fields of science, technology, engineering, and mathematics. Pythagoras was an ancient Greek mathematician and philosopher. Much of his life is shrouded in mystery but he is thought to have been born on the Greek island of Samos around the year 570 BC. He travelled widely in his youth, visiting Egypt and Persia and eventually settled in Southern Italy where he founded a school inspired by a philosophy based around mathematics. Pythagoras has been credited with many mathematical and scientific discoveries, with the most well-known being the Theorem named after him.

The engineering context

Pythagoras Theorem states that the sum of the square of the two sides of a right-angled triangle is equal to the square of the third side, known as the hypotenuse.

This mathematical formula is foundational to engineers and astronomers who use Pythagoras Theorem to calculate the paths of spacecraft, including rockets and satellites. Architects, also, utilise Pythagoras Theorem to calculate the heights of building and the lengths of walls.

Suggested learning outcomes

By the end of this activity students will be able to understand the basics of Pythagoras Theorem and its use and they will be able to measure if something is perpendicular to its base.

Download the free activity sheet below!

All activity sheets and supporting resources are free to download, and all the documents are fully editable, so you can tailor them to your students’ and your schools’ needs.

The activity sheet includes teacher notes, guidance, useful web links, and links (where appropriate) to the national curriculum in each of the four devolved UK nations; England, Northern Ireland, Scotland and Wales.

Please share your classroom learning highlights with us @IETeducation.

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