How many variations are there to rectangles with a perimeter of 24Cm's?

Answer 1

Millions. In fact, an infinite number.

Here are a few to get you started:

6 x 6
5 x 7
4.5 x 7.5
4 x 8
3.5 x 8.5
3 x 9
2.6 x 9.4
2.5 x 9.5
2.4 x 9.6
2 x 10
1.5 x 10.5
1.4 x 10.6
1.3 x 10.7
1.2 x 10.8
1.1 x 10.9
1 x 11