Use Green's theorem $to$ compute the area inside the ellipse

$\frac{x^2}{{18}^2}+\frac{y^2}{{18}^2}=1$

Use the fact that the area can $be$ written $as$

${}_{D}dxdy=\frac{1}{2}{\displaystyle \underset{\text{d}\text{e}\text{l}\text{D}}{\overset{\phantom{}}{}}}-ydx+xdy$

Hint: $x(t)=18cos(t).$

The area $is$