Answer:
147 yards
Step-by-step explanation:
Use a system of equations
Let x be length of rectangle and y be width of rectangle
x = 3y
2x + 2y = 56
Substitute x = 3y into second equation, we have 2(3y) + 2y = 56. Combine like terms and we have 8y = 56. y = 7.
Substituting y = 7 into the first equation, we have x = 3(7), and x = 21.
Area is length times width, so area is 21 * 7 = 147
