Step 1
Write the formula for the area of a segment.
[tex]\frac{\theta}{360}\times\pi r^2-\frac{1}{2}r^2\sin \theta[/tex]
Where
[tex]\begin{gathered} \theta=120^o \\ r=\text{ radius = }\frac{diameter}{2}=\frac{66}{2}=33\text{feet} \\ \pi=3.14 \end{gathered}[/tex]
Step 2
Substitute and find the area of the required segment
[tex](\frac{120}{360}\times3.14\times33^2)-(\frac{1}{2}\times33^2\times\sin \text{ 120)}[/tex][tex]1139.82-471.55=668.27ft^2[/tex]
Hence the area of the segment between the kitchen and the family room that must be replaced is 668.27ft²