Me , i don’t remember how to do this

Me, the vertices of quadrilateral coat are c(2,0), o(7,0), a(7,2) and t(2,2). prove that coat is a rectangle.

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

The price for gasoline is represented by the equation y=3.69x, where y represents the total price for x gallons of gasoline. on a graph, the number of gallons is represented on the horizontal axis, and the total price is represented on the vertical axis. determine whether each statement describes the graph of the equation. select true or false for each statement