Year 5 · Angles and shapes · Summary

Year 5 Angles and shapes: summary and key words

Part of the Year 5 angles and shapes chapter. Chapter overview · whole chapter on one page

Chapter summary

Skill	Method
3-D shapes	A cube has 6 square faces, 12 edges and 8 vertices. A cuboid has 6 rectangular faces, 12 edges and 8 vertices.
Nets	A net is flat. When it folds up, it makes a 3-D shape with the same faces.
Acute, right, obtuse and reflex	Acute: under 90°. Right: exactly 90°. Obtuse: 90° to 180°. Reflex: 180° to 360°.
Protractor	Put the centre on the vertex, line up the 0 line, and read the scale where the other arm crosses it.
Angles on a straight line	They add up to 180°. Find a missing one by taking the known angles away from 180°.
Angles at a point	They add up to 360°. Find a missing one by taking the known angles away from 360°.
Multiples of 90°	A right angle is 90°. A half turn is 180°, a three-quarter turn is 270° and a full turn is 360°.
Rectangles	Four right angles, and opposite sides are equal. Use the perimeter to find a missing side.
Regular and irregular polygons	Regular: all sides equal and all angles equal. Irregular: not both.

I can name and count the faces, edges and vertices of a cube and a cuboid.
I can use a net to name the 3-D shape it makes.
I can name acute, right, obtuse and reflex angles, and say what each one means.
I can measure and draw angles with a protractor.
I can work out a missing angle on a straight line, at a point and in turns.
I know a rectangle has four right angles and opposite sides equal, and I can find a missing side or angle.
I can say whether a polygon is regular or irregular, and explain why.

Face: A flat side of a 3-D shape.
Edge: A line where two faces of a 3-D shape meet.
Vertex: A corner of a shape. More than one is vertices.
Net: A flat pattern that folds up into a 3-D shape.
Angle: The amount of turn between two lines that meet at a point, measured in degrees.
Acute angle: An angle less than 90°.
Obtuse angle: An angle more than 90° and less than 180°.
Reflex angle: An angle more than 180° and less than 360°.
Protractor: A tool for measuring and drawing angles in degrees.
Polygon: A flat shape with straight sides.
Regular polygon: A polygon with all sides equal and all angles equal.
Irregular polygon: A polygon that does not have all sides and all angles equal.