Triangles

There are 116 NRICH Mathematical resources connected to Triangles

problem

Isosceles Seven

Age

14 to 16

Challenge level

Is it possible to find the angles in this rather special isosceles triangle?

problem

Triangle in a Square

Age

7 to 11

Challenge level

Do you agree with Badger's statements? Is Badger's reasoning watertight? Why or why not?

problem

Possible Pairs

Age

7 to 11

Challenge level

In this game, you turn over two cards and try to draw a triangle which has both properties.

problem

Triangle or No Triangle?

Age

5 to 7

Challenge level

Here is a selection of different shapes. Can you work out which ones are triangles, and why?

problem

Name That Triangle!

Age

7 to 11

Challenge level

Can you sketch triangles that fit in the cells in this grid? Which ones are impossible? How do you know?

problem

Triangle transformation

Age

7 to 14

Challenge level

Start with a triangle. Can you cut it up to make a rectangle?

article

Peg and Pin Boards

This article for teachers suggests activities based on pegboards, from pattern generation to finding all possible triangles, for example.

problem

Three Triangles

Age

7 to 11

Challenge level

What do you notice when you put three triangles together?

problem

Constructing Triangles

Age

11 to 14

Challenge level

Generate three random numbers to determine the side lengths of a triangle. What triangles can you draw?

problem

Walking round a triangle

Age

5 to 7

Challenge level

This ladybird is taking a walk round a triangle. Can you see how much he has turned when he gets back to where he started?

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For younger learners

Triangles

Isosceles Seven

Triangle in a Square

Possible Pairs

Triangle or No Triangle?

Name That Triangle!

Triangle transformation

Peg and Pin Boards

Three Triangles

Constructing Triangles

Walking round a triangle