Each participant in a community garden is allotted a rectangular plot that measures 18 feet by 45 feet. How much fencing is needed to enclose each plot?

When you want to know the amount of fencing needed, you have to find the perimeter of the enclosed space. For the shape of a rectangle, the perimeter is the sum of its sides. Its sides consist of 2 equal lengths and 2 equal widths. Therefore:

A = 2L + 2W = 18 (2) + 45 (2) = 126 feet

It will need 126 feet of fencing.