The answer is C: 
Starting with the given formula for the area, A = 1/2hb, the first step is to isolate h by using the multiplicative inverse of b, which is
on both sides of the equation:

The result will be:

The last step is to use the multiplicative inverse of
, which is 2 or
to further isolate the variable <em>h </em>:

The formula for h will be:
which is the option C in your question.
Sqrt(49)*sqrt (-1) -4 = 7i-4
I may be wrong, I think I remember how to do this. A straight line has an angle of 180, so y would be 133, making the area 55571.63u. (u = whatever unit is measuring the circle.) If x = 1/20 of the area, then the red area = 2,778.5u or 2,779u. I hope this helps, but I honestly don't remember how I would find x, and I don't want you to get the question wrong.