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## 'Rotations Are Not Single Round Here' printed from http://nrich.maths.org/

If you haven't seen the problem

'A Roll of Patterned Paper' you may
want to try that first.

In that problem I'd been finding designs for streamers - this
problem follows on from that.

#### I noticed this about the streamers that had rotation symmetry
:

In the ones I tried, if there was one centre of rotation there
always seems to be another centre that worked as well.

#### Your challenge :

Can you find a design with only one centre of rotation?

Or if you thought that was in fact impossible, could you say why
that's true ?

#### Taking it further :

I noticed that if there are mirror lines across the strip, and
if there is also a horizontal mirror line, then the strip always
seems to have rotation symmetry.

Can that be explained?