Question 635952
Area = 1024 

side^2=1024
side = sqrt(1024)

side = 32

Find the diagonal 

Half the doagonal is the radius to cover the entire square garden

32^2+32^2= diagonal ^2 ( Pythagoras theorem)

2048 = diagonal ^2

diagonal = 45.25

Radius = 45.25/2
radius = 22.625 feet