topic badge

8.05 Story problems with area and perimeter

Lesson

Are you ready?

Do you remember how to find the perimeter and area of a rectangle? Let's try this problem to practice.

Find the perimeter of a rectangle with a length of $3$3 m, and a width of $16$16 m.

Learn

To solve problems involving the perimeter and area of rectangles, we will be using these formulas:

  • Perimeter of a Rectangle $=$= $2$2$\times$×Length $+$+ $2$2$\times$×Width
  • Area of a Rectangle $=$= Length$\times$×Width

This video looks at how we can use the area of a rectangle to solve real life problems.

Apply

Question 1

Indu wants to frame her square window with a string of twinkle lights. The window has a side length of $3$3 ft.

  1. Find the length of the string of twinkle lights that Indu needs.

Question 2

Minh is using sticky notes to cover his window. This uses up a total of $70$70 sticky notes, and Minh counts that there are $10$10 sticky notes along the length of the window.

  1. How many sticky notes did Minh use along the width of the window?

 

Remember!

A square is a special type of rectangle that has its length and width equal. This means that we can use the rectangle formulas for perimeter and area for a square as well.

Outcomes

4.MD.A.3

Know and apply the area and perimeter formulas for rectangles in real world and mathematical contexts. For example, find the width of a rectangular room given the area of the flooring and the length, by viewing the area formula as a multiplication equation with an unknown factor.

What is Mathspace

About Mathspace