Year 6 · Angles, Shapes and Circles · Summary

Year 6 Angles, Shapes and Circles: summary and key words

Part of the Year 6 angles, shapes and circles chapter. Chapter overview · whole chapter on one page

Chapter summary

Skill	Method
Straight line	The angles on a straight line add up to 180 degrees.
Angles at a point	The angles at a point add up to 360 degrees.
Vertically opposite	Angles that face each other at a crossing are equal. Angles next to each other add up to 180 degrees.
Triangle	The three angles add up to 180 degrees. An isosceles triangle has two equal base angles.
Quadrilateral and parallelogram	The four angles add up to 360 degrees. In a parallelogram, opposite angles are equal.
Polygon	The interior angles add up to (n − 2) × 180 degrees. In a regular polygon, share the total equally.
Exterior angle	The exterior angles of a polygon add up to 360 degrees. In a regular polygon, each one is 360 ÷ n.
Circle	The diameter is 2 × the radius. Circumference = π × diameter, with π = 3.14 or 22/7.
3-D shapes and nets	A cube has 6 faces, 12 edges and 8 vertices. A net needs one square for each face.

I can find a missing angle on a straight line, at a point and opposite a crossing.
I can find missing angles in triangles and quadrilaterals.
I can work out the interior angles of a polygon, and of a regular polygon.
I can name the radius, diameter and circumference of a circle.
I can find the circumference of a circle using 3.14 or 22/7.
I can draw a shape from its dimensions and angles, and name its sides and angles.
I can count the faces, edges and vertices of a 3-D shape, and check a net.

Radius: The distance from the centre of a circle to its edge.
Diameter: The distance across a circle through its centre. It is twice the radius.
Circumference: The distance all the way round the edge of a circle.
Pi (π): The number that links the circumference and the diameter. We use 3.14 or 22/7.
Interior angle: An angle inside a shape.
Regular polygon: A shape with all its sides equal and all its angles equal.
Vertically opposite: The equal angles that face each other where two straight lines cross.
Net: A flat pattern that folds up to make a 3-D shape.
Prism: A 3-D shape with the same cross-section all the way along, such as a triangular prism.
Pyramid: A 3-D shape with a flat base and triangular faces that meet at a point.