Answer:
165
Step-by-step explanation:
First we need to find the area of the field, A = r^2 * pi
The radius is 290 / 2 = 145 feet
A = 145 * 145 * 3.14 = 66018.5 sqr feet
One bag covers 400 sqr feet
Divide the Area by 400 sqr feet to find number of bags needed.
66018.5 / 400 = 165
He will need at least 165 bags to cover the field