Find the area of a sector with central angel 3pi/2 in a circle with radius 5?

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