The period T (in seconds) of a simple pendulum is a function of its length l (in feet), given by T(l) = 2pi sq root of l/g, where g = 32.2 feet per second per seconds is the acceleration of gravity. Express the length l as a function of the period T.

If T=2pi*sqrt(l/g) then do the inverse operations to get T in terms of l as
g*(T/(2pi))^2=l