If the order matters it is a permutation. For example: if you are selecting 3 people to be on a committee it doesn't matter what order you select them, but if you're selecting three people to be president, vice president, and secretary the order in which you choose them matters the first person being president, the second person being vice president, and the third person be secretary
So since the kitchens long is wide x 2 if you add the 2 longs it makes a wide so you end up with 3 wides technically. So you divide 84 by 3 and u get 28 so make your 2 wides 28. Then u divide 28 by 2 to get 14 so your longs are 14 and your wides are 28 if u add it all together it’s 84.