find area of circle
A=pir^2
A=pi5^2
A=25pi
then find how much the central angle is
whole circle is 2pi radians
(3pi/2)/2pi=3pi/4pi=3/4
it is 3/4 of whole area
area=25pi units^2
3/4 times 25pi=75/4pi units^2=
18 and 3/4 pi square units=
18.75ip square units