Interior angles of a polygon

Maths

Checking understanding of angles from KS2

Securing understanding of angles from KS2

Formalising understanding of triangles from KS2

Formal angle notation

Corresponding angles

Alternate angles

Co-interior angles

Angles on parallel lines traversed by a straight line

The sum of the interior angles of any triangle

Using the sum of the interior angles of a triangle

Deriving the sum of interior angles in multiple ways

Exterior angles of polygons

Interior and exterior angles of regular polygons

Missing angles

Problem solving with polygons

This unit gives pupils the opportunity to explore polygons and begin to generalise their understanding of interior/exterior angles in regular polygons. In the future unit, pupils will use the geometrical properties of a rhombus to perform various constructions

In this unit, pupils learnt how to calculate with angles at a point and angles on a straight line. In this unit, pupils extend their knowledge about angles in lines

In this unit pupils will investigate internal and external angles of polygons and angles made with a transveral and parallel lines. Pupils will develop their ability to formally prove properties of polygons to generalise.

Geometrical properties: polygons

A pentadecagon has 15 sides. The minimum number of triangles that it could be split into is {{}}.

An octadecagon has 18 sides. Which calculation would find the sum of its interior angles?

The interior angles in the hexagon sum to {{}}°.

The interior angles of a pentagon sum to {{}}°.

The size of the angle $$x$$° is {{ }}°. 

An {{}} angle is an angle formed inside a polygon by two of its edges.

The interior angles of a triangle sum to {{}}°.

Starting with the smallest, sort the angles in ascending order of size.

Interior angles of a polygon

Lesson outcome