What’s the domain of the relation graphed here?

How do you find the area of a triangle

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

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