Corresponding angles are a pair of angles at different vertices on the same side of a transversal in equivalent positions.

A pair of angles both between or both outside two line segments that are on opposite sides of the transversal that cuts them.

Co-interior angles are on the same side of the transversal line and in between the two other lines.

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

An exterior angle is an angle on the outside of a polygon between an extension of an edge and its adjacent edge.

Problem solving with polygons

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

Interior angles of a polygon

Deriving the sum of interior angles in multiple ways

Exterior angles of polygons

Interior and exterior angles of regular polygons

Missing angles

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

Angles on the same side of the transversal line and in between the two other lines are called {{}} angles.

Which algebraic statement correctly expresses $$y$$ in terms of $$x$$?

The size of the angle marked in the diagram is {{}}°.

Match each pair of angles with the keywords that describe the relationship between them.

A dodecagon has 12 sides. Find the sum of the interior angles in a dodecagon.

Exterior angles for any polygon sum to {{}}°.

Each exterior angle for a regular hexagon is {{}}°.

Each interior angle in a regular octagon is {{}}°.

The pentagon and hexagon in the diagram are both regular. The angle marked in the diagram is {{}}°.

Problem solving with polygons

Lesson outcome