How do you move a squared variable that is the denominator to the other side of the equation?

It's the same as if you have anything else in the denominator. You can multiply both sides by the squared variable. Example (using "^" for "power"):

a = 1 / b^2

Multiply both sides by b^2:

Step 1: a b^2 = b^2 / b^2

Step 2: a b^2 = 1