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

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

What is the perimeter of a square with a side length of 4 cm? {{  }} cm.

What is the perimeter of a regular triangle with a side length of 4 cm? {{  }} cm.

What is the perimeter of a regular pentagon with a side length of 4 cm? {{  }} cm.

What is the perimeter of a regular octagon with a side length of 4 cm? {{  }} cm.

A regular triangle with a side length of 5 cm

A regular pentagon with a side length of 4 cm

Order these shapes from smallest perimeter to longest.

A regular triangle with a side length of 6 cm 

A regular pentagon with a side length of 3 cm

A regular hexagon with a side length of 3 cm

Which of these shapes will have the same perimeter as each other?

Which of these red lines shows the perimeter of the triangle? 

Match the shape to the correct  number of sides.

Starter Quiz