Skip to main content

2D and 3D shapes and their properties

Pick a shape to see a clear diagram, its properties and an 11+ style question worked through step by step.

Quadrilaterals

Triangles

Polygons

Circles

3D shapes

Quadrilaterals compared

Every quadrilateral has 4 sides and angles that add up to 360°. What tells them apart is their parallel sides, equal sides and symmetry.

ShapeParallel pairsLines of symmetry
Square24
Rectangle22
Trapezium10
Parallelogram20
Rhombus22
Kite01

3D shapes compared

Curved faces count as faces here, as most primary schools count them. The cone's apex counts as a vertex.

Shapes in the 11+

Shape questions test properties rather than names: the missing angle in an isosceles triangle, which quadrilateral has one pair of parallel sides, how many edges a prism has. The 11+ maths topics guide shows where shape fits among the other topics, and the maths glossary explains angles, symmetry, area and volume.

Questions parents ask

What is the difference between a 2D and a 3D shape?

A 2D shape is flat, like a drawing on paper, so it has sides but no thickness. A 3D shape is solid, like an object you can hold: it has faces, edges and vertices.

What is a regular polygon?

A flat shape with straight sides where every side is the same length and every angle is the same size. A regular hexagon has six equal sides and six angles of 120°.

How do you work out the angles inside a polygon?

Take away 2 from the number of sides and multiply by 180. A pentagon has (5 − 2) × 180 = 540°. It works because the shape splits into that many triangles from one corner.

Which shapes do children need for the 11+?

Everything in the Key Stage 2 curriculum: triangles, quadrilaterals, polygons up to ten sides, and common 3D shapes, with their angles, symmetry, faces, edges and vertices. Year 6 covers finding missing angles and making nets.

Shape questions are quick marks in the 11+

Angles, symmetry, nets and 3D shapes come up in 11+ maths and non-verbal reasoning. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.