A farmer planted trees every 2o feet around the arc to protect the large field from the wind. The arc is 225 degrees and has a radius of 510 feet. Which is the closest to the number of trees she planted
The length of the arc is (225/360)*2*pi*510 feet.
Divide this by 20 feet and we get 100.138, so if she plants a tree at 0 feet, then every 20 feet thereafter, she would be able to fit in 101 trees.