Using only whole numbers, how can you draw three rectangles with a perimeter of 12 units?

Answer 1

first recall that perimeter of a rectangle is
P = 2(L+W)
where
L = length
W = width
substituting,
12 = 2(L+W)
6 = L+W
now we need to find for positive, nonzero integers whose sum is 6,, the possible values are:
L=5 and W=1
L=4 and W=2
L=3 and W=3 (this is a square but note that square is also a rectangle)

hope this helps~ :)