Answer:
C.

Explanation:
We proceed to solve for
by the Pythagorean Theorem:
(1)





There are two different solutions:
,

A solution of
is considered realistic when the length of every side of the triangle is a not negative number.














The only realistic set of solutions is for
, and the radius of the circle is represented by the line segment
:

And the area of the circle (
) is calculated from the following formula:



The correct answer is C.