A circle passes through two adjacent vertices A,B of a square and is tangent to the side opposite the side having endpoints A and B. If the sides of the square have length 8 then the radius of the circle is
(a) 19/4
(b) 4
(c) 5
(d) 9/2
d) 16/Pi
(a) 19/4
(b) 4
(c) 5
(d) 9/2
d) 16/Pi
















