Using the sum of the interior angles of a triangle

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

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

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

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

Match the two angles of a triangle with its third angle.

In which of these triangles is there enough information for you to calculate the size of the missing angle?

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

Which of the following are calculations to find the value of $$y$$?

Simplify the following expression $$3x+5y-2x+9y+3x+12$$.

A triangle DEF, where DE = 23 cm, DF = 23 cm and angle EDF is 45° is __________ triangle.

Which of these are correct for the size of the angle marked $$n$$?

...shown that the three angles in a triangle sum to 180°.

...demonstrated that the three angles in a triangle sum to 180°.

...proved that the three angles in a triangle sum to 180°.

Select the statements that best complete the following sentence. By tearing the corners off of a triangle and arranging them together at a point it you have...

Using the sum of the interior angles of a triangle

Lesson outcome