Answer:
4.06 km
Step-by-step explanation:
The area of the sector of a circle is given by the formula ...
A = 1/2r²θ
Filling in the given information, we have ...
31 km² = 1/2(r²)(6π/5)
Solving for r gives ...
r² = (31 km²)(5/(3π)) ≈ 16.446 km² . . . . divide by the coefficient of r²
r ≈ 4.055 km . . . . . . take the square root
The radius of the circle is about 4.06 km.
