1. 

   Hint (a):

   A circle has a total measure of $360°$. To find the area of the shaded sector, you must find the fraction of the circle that is shaded.

   Step 1(a):

   If the smaller angle of the non-shaded area is $90°$, the shaded portion's angle must be $270°$.
   $270°$ as a portion of 
   $360°= \frac{270°}{360°}=\frac{3}{4}$

   Step 2(a):

   This portion represents the fraction of the area that the shaded sector represents in the circle.
   The area of a circle is $π(r^2)$.
   Substituting in $9$ ft for the radius, we get about $254.4$ ft^{$^{2}$} for the total area of the circle.

   Answer (a):

   $\frac{3}{4}$ of $254.4$ ft$^2$$=$ about $190.8$ ft$^2$

b.

3. 

   Answer (c):

   $176.6$ ft^{$^{2}$}