Iam doing circumference and area of circles and am having trouble with some of the questions. for example:

area = 4/pi to the power of two

I don't know the questions you're working on. But I can tell you that
the formula (or equation) in your question doesn't look right to me.

-- If you know the circle's radius, then the circle's area is (pi) x (radius)².

-- If you know the circle's diameter, then the circle's area is (pi/4) x (diameter)².