Egyptian Rope
Daniel and Jaimee
(Tattingstone School) both sent in
carefully drawn solutions for this problem. Each found that three
regular shapes could be made with the rope. Each explained how they
used multiplication or division to work out which shapes could be
made.
Jaimee worked out "which numbers can be multiplied to make 12",
which showed how many sides the shapes would have.
Thinking about it slightly differently, Daniel explained that the
number of knots divided by the number of sides gives how many
'sections' (between knots) there are on each side. For example:
12/4 = 3 means that a shape with four sides (square) has three
knot-sections along each side.
Christina (Marlborough Primary School,
London) found two other types of triangles, in addition to the
equilateral triangle above. She says:
"I know that the two shortest sides in a triangle must add up to
more than the length of the third side, so the longest side of the
triangle can be at most five. The only possibilities are then
and these are exactly the triangles illustrated."
Well done everyone!
