Skip over navigation
Cambridge University Faculty of Mathematics NRich logo
menu search
  • Teachers expand_more
    • Early years
    • Primary
    • Secondary
    • Post-16
    • Events
    • Professional development
  • Students expand_more
    • Primary
    • Secondary
    • Post-16
  • Parents expand_more
    • Early Years
    • Primary
    • Secondary
    • Post-16
  • Problem-Solving Schools
  • About NRICH expand_more
    • About us
    • Impact stories
    • Support us
    • Our funders
    • Contact us
  • search

Or search by topic

Number and algebra

  • The Number System and Place Value
  • Calculations and Numerical Methods
  • Fractions, Decimals, Percentages, Ratio and Proportion
  • Properties of Numbers
  • Patterns, Sequences and Structure
  • Algebraic expressions, equations and formulae
  • Coordinates, Functions and Graphs

Geometry and measure

  • Angles, Polygons, and Geometrical Proof
  • 3D Geometry, Shape and Space
  • Measuring and calculating with units
  • Transformations and constructions
  • Pythagoras and Trigonometry
  • Vectors and Matrices

Probability and statistics

  • Handling, Processing and Representing Data
  • Probability

Working mathematically

  • Thinking mathematically
  • Developing positive attitudes
  • Cross-curricular contexts

Advanced mathematics

  • Decision Mathematics and Combinatorics
  • Advanced Probability and Statistics
  • Mechanics
  • Calculus

For younger learners

  • Early Years Foundation Stage

Triangular Faces

Age 7 to 11
Challenge Level Yellow starYellow star
  • Problem
  • Getting Started
  • Student Solutions
  • Teachers' Resources

Suppose we start with two types of triangles:
2 starttris
 
and we have lots of them ready to cut out and use (you could print off this sheet).
 
SmYellGreen


We will be putting them together to make 3D shapes.
Sometimes you need tabs to glue them together so you cut those out like these (here is a sheet of triangles with tabs):

Tabs
Well here is an image of 3D shape number 1 made from 6 green and 4 yellow triangles:
3d1
 
and here is a net that could be used to make it:
pict4
Have a go at making this or something similar. You might make it from a net or just by sticking the triangles together.
-----------------------------------------------------
 
Here is an image of 3D shape number 2:
3D2
 
This was made from 6 yellows and 2 greens.
Can you try and make it, and work out a net for it?
-----------------------------------------------------
 
Here is the last one of mine to try, made from 4 green and 2 yellow:
3d3

See if you can make this one and discover a simple net for it.

You may also like

Construct-o-straws

Make a cube out of straws and have a go at this practical challenge.

Matchsticks

Reasoning about the number of matches needed to build squares that share their sides.

Little Boxes

How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?

  • Tech help
  • Accessibility Statement
  • Sign up to our newsletter
  • Twitter X logo

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

University of Cambridge logo NRICH logo