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

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

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

This number shape is made of smaller squares. Complete the sentence. This shape has a perimeter of {{  }} units.

Equal-sized matchsticks have been used to find the approximate perimeter of this square. The square has a perimeter of around {{  }} units.

Count the units around the outside of the shape.

How can you find the perimeter of this shape?

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

Not counting one of the sides of the shape.

Lucas says the perimeter of the shape is 10 units. What mistake might he have made?

Which of these shows the correct way to measure the line?

Which of these shows the perimeter of the triangle?

Which of these shapes has a different perimeter to the other two?

Select all of the statements that are true of this number shape.

Yes, but it depends on the distance around them. 

Yes, because all rectangles have the same perimeter.

No. If they are two different rectangles they must have a different perimeter. 

Is it possible for two different rectangles to have the same perimeter?

It is impossible to say which one has a bigger perimeter.

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

Lesson outcome