## Algebra 2 (1st Edition)

The standard form of the equation of a circle with a center in the origin and radius $r$ is: $x^2+y^2=r^2$. (Consider the bridge as the origin) Plugging in the values we get: $x^2+y^2=(-25)^2+40^2=625+1600=2225\lt2500=50^2=r^2$. Thus we are within the region.