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

Maths

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.

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.

This lesson will soon be taken down.

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

Lesson outcome