Shapes, Angles and Lines
In Year 3, geometry is about looking carefully at shapes, lines and corners and learning to describe them. Children name 2-D shapes by counting their sides, work out the perimeter by adding up the distance all the way round, and begin to sort the lines and angles they notice in the world. None of it is as daunting as it sounds: a triangle is simply a shape with three sides, and a corner that makes a neat quarter turn is a right angle.
Practise Shapes, Angles and Lines
Have a guess, even if you're not sure. Get one wrong and we'll show you why, so every miss is a chance to learn.
Timed practice
The same practice, just with a gentle clock. Pick a length and see how many you can answer.
Good to know
Shapes and angles
Here is your shape and angle spotter to lean on while you practise.
2D shapes
Angle types
Lines
Four kinds of line to spot and name. The last two come in pairs, so look at what the two lines are doing to each other.
For grown-ups
Two ideas do most of the work this year. The first is the right angle, the square corner you find on a book or a door, which becomes the yardstick everything else is measured against: an angle is bigger or smaller depending on how far it opens, not on how long its lines are drawn. The second is the language of lines, horizontal and vertical, parallel lines that stay the same distance apart and never meet, and perpendicular lines that cross at a right angle. Learning to name what they can see now is what lets children measure angles in degrees, classify shapes and reason about geometry properly in later years.
What is in this topic
- Naming 2-D shapes by their number of sides
- Working out the perimeter of a shape
- Horizontal, vertical, parallel and perpendicular lines
- Recognising right angles
- Comparing angles to a right angle
- Name 3-D shapes and count their faces, edges and vertices
How to help at home
Geometry sticks fastest when it is something you point at in the real world, not just words on a card, so go looking for shapes and corners together.
- Count the sides out loud to name a shape. Trace round the edge with a finger: 3 sides is a triangle, 4 a square or rectangle, 5 a pentagon, 6 a hexagon. The number of sides is the whole game.
- Use the corner of a book or a piece of paper as a right-angle checker. Hold it into a corner: if it fits perfectly the angle is a right angle, a quarter turn, like the corner of a door.
- Compare every other angle to that right angle. If the corner is more open than the book corner it is bigger than a right angle; if it is more closed, it is smaller. That comparison matters more than any name.
- Spot the line types around the house. A windowsill is horizontal, a door edge is vertical, the cross of a window frame is perpendicular (two lines meeting at a right angle), and railway tracks or ladder sides are parallel (always the same distance apart, never meeting).
Where children get stuck
The most common trip-up is judging an angle by the length of its lines instead of how open it is. A child will say a wide angle drawn with short lines is small, and a narrow angle drawn with long lines is big. It is the amount of turn between the two lines that counts, not how long they are. Drawing the same angle once with short arms and once with long arms shows that the opening has not changed at all.
The other wobble is muddling parallel and perpendicular. A quick way to keep them apart: parallel lines are like two friends walking side by side, always the same gap apart and never meeting, while perpendicular lines cross and make a right angle where they meet, like a plus sign or the corner of a square. Ask which one makes a neat square corner, and they will land on perpendicular.