A right-angled triangle has one 90° angle. Right-angled triangles can be classified as isosceles or scalene.

Equilateral triangles have 3 equal sides and 3 equal angles.

Isosceles triangles have 2 equal sides and 2 equal angles.

Scalene triangles have no equal sides and no equal angles.

Explore, sort and classify triangles

Maths

In this unit pupils will pupils will complete and compose symmetrical shapes from two congruent shapes and investigate lines of symmetry in 2D shapes. In the future unit pupils will explain what area is and measure using counting as a strategy. They will make different shapes with the same area and compare the area of different shapes. 

In the prior unit pupils investigated ways to compose and decompose polygons. They investigated quadrilaterals with and without parallel and perpendicular sides. In this unit pupils will complete and compose symmetrical shapes from two congruent shapes and investigate lines of symmetry in 2D shapes.

Properties of 2D and 3D shapes and symmetry

Which of these is true for all right-angled triangles?

These triangles have been sorted. What type of triangles are in this set?

These triangles have been sorted. Which triangle has been incorrectly sorted?

True or false. Right-angled triangles can be scalene or isosceles.

Jacob has made these triangles. Match the triangle to the correct description.

This shape is a right-angled {{ }} triangle.

Which of these statements describe the properties of all triangles? 

True or false. The images are all triangles.

Match the different triangles to their properties.

How many equal sides and equal angles does an isosceles triangle have? {{ }}

A triangle with 3 equal sides and 3 equal angles is called an __________ triangle.

How many equal sides and equal angles does a scalene triangle have?

This lesson will soon be taken down.

Explore, sort and classify triangles

Lesson outcome