Answer:
21%
Step-by-step explanation:
Area of one sprinkler
a = πr²
a = π10²
a = 314.159 ft²
8 sprinklers
a = 8 * 314.159
a = 2,513.272
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area of field
a = lw
a = 80 * 40
a = 3200
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area not watered
a = 3200 - 2,513.272
a = 686.728
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percentage not watered
p = 686.728 / 3200 * 100%
p = 21.46025%
Rounded
21%
