When plugging in the area of a circle formula, I ran into something I can't figure out.

Lets say that the radius is (5 sqr root of 2/2) Its a fraction. When plugging it into the formula, it becomes (5 sqr root of 2/2)^2. I know the correct answer is 25/2, however, that is what I am not understanding.

Please clarify for me: Pretending that it is not in fraction form, 5 sqr root of 2 * 5 sqr root of 2 would equal 50, correct?

It becomes 25 * 2= 50, correct?