To the nearest tenth, what is the area of the shaded segment when ja = 8 ft?

I think you forgot to give the diagram along with the question. Considering 8 ft as the radius, we can find the area by the formula described below.
Area = pi * (Radius) ^2
         = 3.14 * (8)^2
         = 3.14 * 64
         = 200.96
So the area of the shaded portion would be 200.96 square feet. I hope that this answer has come to your help.