Essentially a factors question.

Eg: 144 = 1 x 1 x 144

Condition 1: Perimeter of top surface is 22 cm

Condition 2: All lengths are more than 2

Combination: 144 = 3 x 8 x 6 with top surface 3 cm and 8 cm (do perimeter is 3 + 8 + 3 + 8 = 22 cm)

So the height is 6 cm

I don’t understand the combination part

We need to find three numbers such that they multiply to 144. Can be repeated numbers or can all be different.

It’s more of guesswork.

The fact that the three numbers are greater than 2 means you can try out 3 as the first number. Then you notice that 144/3 = 48 = 8 x 6. It so happens that 3 + 8 = 11 and doubling this will get you 22, the required perimeter. The other length, 6, must be the height.

The possible combinations of three numbers which multiply to 144 are these

144 = 3 x 6 x 8
144 = 3 x 4 x 12
144 = 3 x 3 x 16
144 = 4 x 4 x 9
144 = 4 x 6 x 6

(No more already)

Then from the list, you must find two numbers that add to 11 (half the perimeter of the rectangle)