Question 612402
This is a perimeter of a rectangle problem.  Perimeter (P) of a rectangle is the sum of all sides
P = 2 x length + 2 x width.

In this problem the Perimeter (P) = The amount needed for the area Tom wants to enclose
Question: How many yards are leftover?
Leftover = Amount bought – amount needed
 
Given information: 
Rectangle = 30 yards long by 20 yards wide 
Amount Bought =  125 yards

Step 1:  Find the Perimeter(P)of rectangle 30 yards long and 20 yards wide.
	P = 2 x length + 2 x width.
	P = (2 x 30) + (2 x 20)
	P = 60 + 40
	P = 100

Step 2: Find the yards leftover.  
	Leftover = Bought – Needed 
	Leftover = 125 - Perimeter
	Leftover = 125 - 100 
	Leftover = 25

Answer:  25 yards is leftover