### Rotating Triangle

What happens to the perimeter of triangle ABC as the two smaller circles change size and roll around inside the bigger circle?

### Doodles

Draw a 'doodle' - a closed intersecting curve drawn without taking pencil from paper. What can you prove about the intersections?

### Russian Cubes

I want some cubes painted with three blue faces and three red faces. How many different cubes can be painted like that?

# L-triominoes

##### Stage: 4 Challenge Level:
Look at the picture below showing different odd sizes of triomino.

Can you see a way to build round the red triomino to make the orange one?
To build round the orange one to make the grey one?
Can you continue to make a size $7$ triomino? And then a size $9$?