Explanation:
since it is a square (all 4 sides are equally long), we only needed one side.
logically, the second side has the same size as the first.
a perimeter is the total length of a trip around the whole shape.
in our case that means a trip along all 4 sides (again, they are all equal).
so, the perimeter is
4 × (4 1/2) cm
first, let's convert the mixed fraction into a full fraction :
4 1/2 = (4×2 + 1)/2 = (8 + 1)/2 = 9/2
and now we can calculate it easily
4 × 9/2 = 36/2 = 18 cm
the perimeter is 18 cm.