If you were to fold a shape on its line of symmetry, both halves would match exactly.

Another term for a line of symmetry. If you were to fold a shape on its line of symmetry, both halves would match exactly.

When you reflect a shape, you flip it over a mirror line or line of symmetry without turning it or changing the size.

Reflect polygons in a line of symmetry

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

The mirror image of a shape is a __________ of it.

True or false. This image shows a reflection.

Sam is using vertices to reflect this shape. Which vertex has been placed in the wrong position on the grid?

The 'reflected' shape is a different size.

The 'reflected' shape is not the same distance from the mirror line.

The 'reflected' shape has not been flipped.

Complete the sentence. This image does not show a reflection because __________.

Which of these shapes are regular polygons?

An equilateral triangle has ___ lines of symmetry.

This shape is a regular pentagon. It has {{ }} lines of symmetry. 

The number of lines of symmetry in a __________ is equal to the number of sides.

True or false. An isosceles triangle has 3 lines of symmetry.

Squares and rectangles both have 4 lines of symmetry.

A rectangle has more lines of symmetry than a square.

A square has 4 lines of symmetry, and a rectangle has 2 lines of symmetry.

Squares and rectangles are both regular polygons.

This lesson will soon be taken down.

Reflect polygons in a line of symmetry

Lesson outcome