the top of a ramp is 4 feet above the ground. the ramp makes a 21.3 degree anngle with the ground. what is the length of the ramp

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field