Answer
31 feet
Work Step by Step
We have a circular pattern to water for a square garden. The furthest place to water in the garden is a corner of the garden.
Area of square garden = 920 $ft^2$
Side-length = $x$
$x*x=920$
$x^2=920$
$\sqrt {x^2} = \sqrt {920}$
$x=30.3315$
Since this is the furthest place on the garden for the sprinkler to water, this is the radius of the circle. However, we must round to the closest whole number that would water the entire garden. A radius of 30 feet would not water the entire garden, so a radius of 31 feet is needed.