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Video:What's the Formula for Finding Area and Perimeter of a Rectangle?

with Maria Birch

Want to learn about the formula for finding area and perimeter of a rectangle? Here, see instructions and tips for using the formula.See Transcript

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Transcript:What's the Formula for Finding Area and Perimeter of a Rectangle?

Hi, I'm Maria Birch and in this video, I'm going to show you how to find the area and perimeter of a rectangle.

Information About Finding Area and Perimeter of a Rectangle

As a reminder, a rectangle is a quadrilateral where all four interior angles are 90 degrees. The opposite sides of a rectangle are always parallel and equal in length.The formula for finding the area of a rectangle is very easy, you simply multiply the length of the rectangle by the width. Therefore Area = Length x Width. And one thing to keep in mind is that area is always expressed as a unit of measurement squared.

Examples for Finding Area and Perimeter of a Rectangle

I'll show you some examples:Lets say you have a rectangle that's 6 inches long by 4 inches wide. The area would equal 6 x 4, which equals 24 inches squared.Here's another example: if the rectangle is 8 inches long by 2 inches wide, the area would equal 8 x 2, which equals 16 inches squared. Now lets move on to finding the perimeter of a rectangle. The perimeter is the total distance around the outside of a rectangle.

To calculate the perimeter, we add the width and the length and the width and the length of the rectangle. The formula is written as Perimeter = 2(length) + 2(width). As you can see, the formula can be written in various ways that mean the same thing.So let's do a couple of examples: If the length of a rectangle is 3 inches and the width is 1 inch, the perimeter = 2(3in) + 2(1in) = 8 in. So the perimeter is 8 inches.

In another example, the length of our rectangle is 5 inches and the width is 4 inches. So 2(5in) + 2(4in) = 18. Therefore the perimeter of this rectangle is 18 inches. So that's how you calculate the area and perimeter of a rectangle.

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