The picture in the attached figure
we know that
the angle measurement of central angle QRS is less than pi radians
area of the circle=pi*r²
for r=18 units
area of the circle=pi*18²------> 324*pi units²
area of the half of a circle=324*pi/2-----> 162*pi units²
area of a quarter of a circle=324*pi/4----> 81*pi units²
<span>analyzing the graph we can say that the shaded area is smaller than the area of the middle of a circle but it is larger than the area of a quarter of a circle
</span>so
the area of the shaded sector < 162*pi units²
and
the area of the shaded sector > 81*pi units²
therefore
the answer must be 144*pi units²
we know that
the angle measurement of central angle QRS is less than pi radians
area of the circle=pi*r²
for r=18 units
area of the circle=pi*18²------> 324*pi units²
area of the half of a circle=324*pi/2-----> 162*pi units²
area of a quarter of a circle=324*pi/4----> 81*pi units²
<span>analyzing the graph we can say that the shaded area is smaller than the area of the middle of a circle but it is larger than the area of a quarter of a circle
</span>so
the area of the shaded sector < 162*pi units²
and
the area of the shaded sector > 81*pi units²
therefore
the answer must be 144*pi units²