A farmer uses an irrigation sprinkler system that pivots about the center of a circular field. Determine the length of the sprinkler if an area of 2340 square feet is watered after a pivot of 20°.

Question

A farmer uses an irrigation sprinkler system that pivots about the center of a circular field.  Determine the length of the sprinkler if an area of 2340 square feet is watered after a pivot of 20°.

P.S: The formula is A=1/2 theta r^2
Please help me. Thank you.

Scott · Answer

Θ is in radians 20º = (2 π / 18) rad 2340 = ½ (2 π / 18) r² 18 * 2340 / π = r²

olly · Answer

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