Learn with TayoMaths Skills · Topic 19
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Module 4: Geometry basics · Topic 19 of 26

2D and 3D shapes

Properties of shapes, symmetry, nets and plans

VIDEO LESSON Watch Mr Boston explain 2d and 3d shapes
Mr Boston
Mr Boston

Shapes are everywhere. Knowing their properties helps with everything from wrapping presents to designing a room.

Shape properties

  • Triangles: equilateral (3 equal sides), isosceles (2 equal sides), scalene (no equal sides), right-angled.
  • Quadrilaterals: square, rectangle, rhombus, parallelogram, trapezium, kite.
  • Polygons: pentagon (5), hexagon (6), heptagon (7), octagon (8), decagon (10).
  • 3D shapes have faces, edges and vertices (corners). A cube has 6 faces, 12 edges and 8 vertices.
  • A net is a flat shape that folds into a 3D shape.

Worked examples

Example 1. How many lines of symmetry does a regular hexagon have?

A regular polygon has as many lines of symmetry as sides: 6.

Example 2. How many faces, edges and vertices does a triangular prism have?

5 faces (2 triangles, 3 rectangles), 9 edges and 6 vertices.

Example 3. Which quadrilateral has exactly one pair of parallel sides?

A trapezium.

Top tips and common mistakes

  • Euler’s rule: faces + vertices − edges = 2 for these solids. Cube: 6 + 8 − 12 = 2.
  • A square is a special rectangle and also a special rhombus.
  • Plans and elevations are views from above, the front and the side.
Tayo
Tayo

Bees build hexagons because they fit together with no gaps. Clever bees!

Practise

Answer as many as you like. Every question is new, and you get a “correct” tick for each one you get right first time. Use “Show answer” to see a worked solution.

Quiz: earn your stamp

Printable worksheet

Worksheet preview: 2D and 3D shapes

2D and 3D shapes worksheet. The questions come first and the answers for grown-ups are on the last page, so you can print just the question pages.

Download the worksheet (PDF)

Printing is optional. A4 size.