The distance around a two-dimensional shape.

Know that perimeter can be calculated by adding together the side lengths of a 2D shape

Maths

Know that a regular polygon has sides that are the same length and angles that are the same size

Know that the perimeter is the distance around a 2D shape

Understand that different shapes can have the same perimeter

Know that perimeter is measured in units of length and can be found by counting or measuring units

Know that the perimeter of a rectangle can be calculated by addition and multiplication

Know that unknown side lengths can be calculated from the perimeter and known side lengths

Understand that the perimeter of a regular polygon can be calculated by multiplication

Calculate the side length of a regular polygon by division where the perimeter is known

Solve problems involving the perimeter and side lengths of polygons

In this unit pupil will learn perimeter as the distance around the edge of a 2D shape. They will learn perimeter is measured in units of length found by counting units and by calculating by adding the side lengths of a 2D shape. In the future unit pupils will pupils will complete and compose symmetrical shapes from two congruent shapes and investigate lines of symmetry in 2D 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 pupil will learn perimeter as the distance around the edge of a 2D shape. They will learn perimeter is measured in units of length found by counting units and by calculating by adding the side lengths of a 2D shape.

In this unit pupil will learn perimeter as the distance around the edge of a 2D shape. They will learn perimeter is measured in units of length found by counting units and by calculating by adding the side lengths of a 2D shape.

Perimeter

Which calculations could be used to work out the perimeter of the number shape?

Use adding to find the perimeter of the shape. The perimeter is {{  }} units.

Laura says the perimeter of this shape is 6 units. What mistake do you think she has made?

What is the perimeter of this shape? {{  }} units.

There is not enough information to work out the perimeter of this rectangle.

You can work out the perimeter of the rectangle by calculating 4 + 5 + 4 + 5

You can work out the perimeter of the rectangle by calculating 5 + 5 + 4 + 4

What is the perimeter of this square? {{  }} units.

Match the unit of measure to the correct abbreviation.

This shape has a perimeter of {{  }} units.

What is the perimeter of this shape?{{  }} units.

Know that perimeter can be calculated by adding together the side lengths of a 2D shape

Lesson outcome