What happens to these capital letters when they are rotated through one half turn, or flipped sideways and from top to bottom?

Sort the frieze patterns into seven pairs according to the way in which the motif is repeated.

See the effects of some combined transformations on a shape. Can you describe what the individual transformations do?

Patterns that repeat in a line are strangely interesting. How many types are there and how do you tell one type from another?

How many different transformations can you find made up from combinations of R, S and their inverses? Can you be sure that you have found them all?

A gallery of beautiful photos of cast ironwork friezes in Australia with a mathematical discussion of the classification of frieze patterns.

Does changing the order of transformations always/sometimes/never produce the same transformation?

Jenny Murray describes the mathematical processes behind making patchwork in this article for students.

Proofs that there are only seven frieze patterns involve complicated group theory. The symmetries of a cylinder provide an easier approach.

This article looks at the importance in mathematics of representing places and spaces mathematics. Many famous mathematicians have spent time working on problems that involve moving and mapping. . . .

Have you ever noticed how mathematical ideas are often used in patterns that we see all around us? This article describes the life of Escher who was a passionate believer that maths and art can be. . . .

Why not challenge a friend to play this transformation game?

This problem is based on the idea of building patterns using transformations.

This was a problem for our birthday website. Can you use four of these pieces to form a square? How about making a square with all five pieces?

In this trail, a new type of NRICH resource, learn about transformations of graphs. Given patterns made from families of graphs find all the equations in the family.

Explore the effect of reflecting in two parallel mirror lines.

Explore the effect of reflecting in two intersecting mirror lines.

How many differently shaped rectangles can you build using these equilateral and isosceles triangles? Can you make a square?

Can you make the most extraordinary, the most amazing, the most unusual patterns/designs from these triangles which are made in a special way?

NRICH December 2006 advent calendar - a new tangram for each day in the run-up to Christmas.

An introduction to groups using transformations, following on from the October 2006 Stage 3 problems.

Find out how we can describe the "symmetries" of this triangle and investigate some combinations of rotating and flipping it.

Investigate how the four L-shapes fit together to make an enlarged L-shape. You could explore this idea with other shapes too.

Can you fit the tangram pieces into the outline of Wai Ping, Wah Ming and Chi Wing?

Can you fit the tangram pieces into the outline of Mai Ling?

Can you fit the tangram pieces into the outline of the rocket?

Can you fit the tangram pieces into the outline of this junk?

How can the same pieces of the tangram make this bowl before and after it was chipped? Use the interactivity to try and work out what is going on!

A cylindrical helix is just a spiral on a cylinder, like an ordinary spring or the thread on a bolt. If I turn a left-handed helix over (top to bottom) does it become a right handed helix?

Can you fit the tangram pieces into the outlines of the chairs?

Can you fit the tangram pieces into the outline of these rabbits?

Can you fit the tangram pieces into the outline of this goat and giraffe?

Can you fit the tangram pieces into the outline of Granma T?

Can you fit the tangram pieces into the outline of the child walking home from school?

Can you fit the tangram pieces into the outlines of these clocks?

Can you cut up a square in the way shown and make the pieces into a triangle?

Can you fit the tangram pieces into the outline of this shape. How would you describe it?

Can you fit the tangram pieces into the outlines of Mai Ling and Chi Wing?

Can you fit the tangram pieces into the outlines of these people?

Can you fit the tangram pieces into the outline of this brazier for roasting chestnuts?

Explore the effect of combining enlargements.

Cut a square of paper into three pieces as shown. Now,can you use the 3 pieces to make a large triangle, a parallelogram and the square again?

Can you fit the tangram pieces into the outline of this telephone?

Can you fit the tangram pieces into the outline of Little Ming playing the board game?

Can you fit the tangram pieces into the outline of Little Fung at the table?

Can you fit the tangram pieces into the outlines of the watering can and man in a boat?

Can you fit the tangram pieces into the outlines of the lobster, yacht and cyclist?

Find a way to cut a 4 by 4 square into only two pieces, then rejoin the two pieces to make an L shape 6 units high.