Question

Which is the best strategy to use to solve this problem? Sophie wants to make a large rectangular sign that has an area of 60 square feet. She wants to put a border around the sign, but she wants to use as little border material as possible. What are the dimensions Sophie should use for this sign?

A. Write a number sentence. Use a number sentence to calculate the area of a rectangle. Use guess and check to find two numbers that when multiplied will give a product of 60.

B. Make a list. Create a list of all possible whole-number combinations of length and width that would equal an area of 60 square feet. Then start calculating the perimeter of each rectangle. Look for a pattern to decrease the number of calculations you have to make.

C. Use objects to model the problem. Arrange 60 square tiles in different patterns that create a rectangular shape. Count the number of tiles on the perimeter of each of the shapes.

Answer 1

Answer: All of the plans could get you to the correct answer. However, being able to write and solve an equation would generally be the fastest. Therefore, I would chose choice A.

In this problem, you are dealing with 2 separate equations. First, you need to find the volume, so A = LW. And you are also dealing with the perimeter formula, P = 2L + 2W.

All you need to do is find option for the area that gives the smallest perimeter.