Answer
About 322.54 in$^2$
Work Step by Step
120$^{\circ}$ is one third of the rotation of a circle.
radius of the large circle=R=18
radius of the small circle=r=4
A=$\frac{1}{3}$$\pi$R$^2$-$\frac{1}{3}$$\pi$r$^2$
A=$\frac{1}{3}$$\pi$(18)$^2$-$\frac{1}{3}$$\pi$(4)$^2$
A=108$\pi$-$\frac{16}{3}$$\pi$
A$\approx$322.54
