Finding the best solution for this problem depended on thinking very carefully about what was meant by DIFFERENT ways of arranging the five triangles.

For example: Christine Ivanova (Age 11, Malborough School) explained, "There is only one shape from the hexagon group because when this shape is rotated it looks like different shapes but it is just one basic shape".

As Sophie Peterken said: "There were 4 different shapes using all five equilateral triangles, without rotating the shapes. The shapes I made were: one was long and thin, but was not a perfect line because it had 3 triangles on one side and2 triangles on the top side. The second shape had 4 triangles sloping upwards, and one triangle on the side of it. The third shape was a big triangle with a smaller triangle on the side of the top one. And the fourth shape was shaped in the way of a croissant, and had three triangles in a row, and two on top of the two end triangles."

Leyla Aksu (Age:12, Private IRMAK Primary School, Istanbul, Turkey) sent in drawings of the four ways:

Merve Ertan (Age:12, Private IRMAK Primary School, Istanbul, Turkey) agreed with this set of four shapes too.

Caroline Foster & Rebecca Sherwood (The Mount School, York) also realised that some shapes they found were really the same as others if you turned them around or flipped them over. " We found six different ones, but two of these are reflections in a way, so maybe it's only four".

Kirstine Heald (Age 10, Tattingstone School) also saw how to group some 'variations' of the same shape together

However, if you decided to think about each position of the shape as being different, then there would be many shapes in your solution. Ece Demir (Age12, Private Irmak Primary School) found 18 shapes. Do think there are any more? Christopher Bold (Age 10, Tattingstone School) found two more variations of the straight line.

Well done to everyone else who sent in some shapes.