Use your mouse to move the red and green parts of this disc. Can you make images which show the turnings described?
Can you sort these triangles into three different families and explain how you did it?
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
How much do you have to turn these dials by in order to unlock the safes?
Can you describe the journey to each of the six places on these maps? How would you turn at each junction?
The triangles in these sets are similar - can you work out the lengths of the sides which have question marks?
Watch this film carefully. Can you find a general rule for explaining when the dot will be this same distance from the horizontal axis?
We had some very detailed solutions to this problem - well done!
Go to last month's problems to see more solutions.
Bernard Bagnall describes how to get more out of some favourite NRICH investigations.
How good are you at estimating angles?