Can someone explain how to find the answer for this pre-calculus question?
select the best answer.
cot a sin 2a=
a. 1 + cosa
b. 1 + sin2a
c. 1 + cos2a

Anew landowner is interested in constructing a fence around the perimeter of her property. her property is 1,080√30 feet wide and 500√20 feet long. what is the perimeter of the property? (recall that the perimeter is the sum of each side of a shape or boundary). a 1,580√40 feet b. 5,320√5 feet c. 3,160√20 feet d. 10,640√5 feet