Chapter 10 - Area - 10-7 Areas of Circles and Sectors - Practice and Problem-Solving Exercises - Page 663: 11

$282,743 \ ft^2$

Let $A$ be the area of a circle. The area $(A)$ of a circle whose radius is $R$ is given by: $A=\pi r^2 ...(1)$ We are given that irrigation arm corresponds to radius. Thus, $r=300 \ ft$ Plug the data in the equation (1) to obtain: $A=\pi (300)^2=\pi(90000)$ Therefore, we get , $Area=90000 \ \pi \approx 282,743 \ ft^2$