Amy draws all triangles which perimeter is 20 cm and length of sides are integers. How many different types of triangle(s) does she draw? (triangles with sides 4,5,6 and 4,6,5 are regarded as the same type of triangle)
Obviously the sides have to add to 20 and they have to be integers.
the only other rule is that the 2 little sides have to add to be more than the length of the 3rd side
The longest one cannot be 19 the two little ones cannot add to 19
Can the longest one be 18?
work your way down and work out what triples can work.
Give it a go yourself :))