Year 3 geometry introduces right angles and perimeter, and deepens knowledge of 2D shape properties such as sides, corners and angles.
What your child will learn
- Identify right angles in shapes
- Name and describe pentagons, hexagons, octagons and rhombuses
- Measure the perimeter of squares and rectangles
- Describe shapes by their properties
Right angles
A right angle is a square corner — like the corner of a book or a door frame. Squares and rectangles have four; a right-angled triangle has one.
Perimeter
Perimeter is the total distance around the outside of a shape. For a rectangle 6 cm long and 3 cm wide, add all four sides: 6 + 3 + 6 + 3 = 18 cm. A frequent mix-up is multiplying the sides, which finds the area instead.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. What 3D shape is this tin?
🥫- Sphere
- Cylinder
- Cube
- Cone
Show answer
Answer: Cylinder. A tin is shaped like a cylinder.
2. Which shape has 4 sides?
- Right-angled triangle
- Square
- Pentagon
- Octagon
Show answer
Answer: Square. A square has 4 straight sides and 4 corners.
3. Which shape has 5 sides?
- Hexagon
- Triangle
- Pentagon
- Square
Show answer
Answer: Pentagon. A pentagon has 5 straight sides and 5 corners.
Tips for grown-ups
- Use a folded paper corner as a right-angle checker around the house.
- Measure the perimeter of a table, book or tablet with a ruler.