Chapter 9: Angles and shapes

By the end of this chapter you will be able to

• Name the faces, edges and vertices of a cube and a cuboid, and say what a net folds into
• Name an angle as acute, right, obtuse or reflex, and estimate its size by comparing it with a right angle
• Measure and draw angles in degrees with a protractor, and read a reflex angle from the small angle next to it
• Find a missing angle on a straight line (180 degrees), at a point (360 degrees), and in turns of 90 degrees
• Use the properties of rectangles to find missing sides and angles
• Tell regular polygons from irregular ones by their equal sides and equal angles

You should already know

• Right angles, quarter turns and 2-D shapes (Year 4, Chapter 9)
• Perimeter of rectangles and composite shapes (Year 5, Chapter 8)
• Multiplying and dividing by 10, 100 and small numbers (Chapters 4 and 5)

Where this leads

• Reflection and translation of shapes on a grid (Year 5, Chapter 10)
• Angles in triangles and quadrilaterals, and angles on parallel lines (Year 6, Chapter 10)
• Circles and regular polygons with angles in more detail (Year 6, Chapter 10)