A polygon is a flat (2D), closed figure made up of straight line segments.

A regular polygon has sides that are all equal and interior (inside) angles that are all equal.

An irregular polygon has sides that are not equal or interior (inside) angles that are not equal.

Checking and securing understanding of polygons

Maths

In this unit, pupils applied their understanding of angles to solve increasingly complex problems. In the future unit, pupils will use their mathematical reasoning to derive and use various circle theorems. 

In the prior unit, pupils learnt how to identify corresponding, alternate and co-interior angles. In this unit, pupils use their knowledge of these angles to reason through and solve more complicated problems.

Angles

A {{}} polygon has sides that are all equal and interior (inside) angles that are all equal.

An {{}} polygon has sides that are not equal or interior (inside) angles that are not equal.

Not all of its interior angles are the same size.

Not all of its sides are the same length.

Why is the octagon in the image not regular?

The perimeter of the heptagon is {{}} cm.

An equilateral triangle has __________ equal angles.

A square has length 5 cm. Its perimeter is {{}} cm.

A rhombus has a base of length 5 cm. Which statement is true about its perimeter?

This lesson will soon be taken down.

Checking and securing understanding of polygons

Lesson outcome