Area of a Square

Lesson Objective

In this lesson, we will learn about the area of a square.

About This Lesson

In this lesson, we will:

Learn about the formula for the area of a square.
See an example on using the formula to find a square's area
See another example on using the formula to find the length of the sides (edges).

The study tips and math video below will explain more.

Study Tips

Tip #1

A square has four right angles and all the sides of a square have the same length.

Now, if the length of each side is L, the area, A of the square will be:

A = L²

The math video below will give more explanations on this. Also, we will see some examples on how to use the formula.

Math Video

Lesson Video

If the above player doesn't work, try this direct link.

Math Video Transcript

00:00:03.180
In this lesson, we will learn about the area of a square.

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Consider this square. All the sides of this square have the same length, L.

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Now, we can get the area of this square, A, by multiplying both of these length L together.

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With this, we get the area, A, equals to L multiply by L. This gives L square.

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Note that, we also must include the unit. Since we are multiplying these 2 lengths together, the unit for the area will be in the form of square unit.

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We will see the explanations on this, in the upcoming example.

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Now, Let’s see some examples on using this formula.

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Find the area of this square when the length of each side is 3cm.

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To do so, we start with the formula for the area of a square, A equals to L square.

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Since the length of each side is 3 cm, we can substitute L with 3.

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This gives 3 square.

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Now, let's simplify 3 square.  3 square is actually the same as, 3 multiply by 3, which is 9.

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Let's write down this number.

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Now, this number is meaningless unless we include the unit for it.

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Since the length is given in centimeter, the unit for the area will be in square centimeter.

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Therefore, the area of this square is 9 square centimeter.

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Next example, given that the area of this square is 4 square feet, find the length of each side.

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Now, we start with the formula for the area of a square, A equals to L square.

00:02:03.180
Since the value of the area is given, we can find the length of each side, by solving the equation for L.

00:02:11.060
Here’s how. Since the area is given as 4 square feet, we can substitute A with 4.  

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Now, we have, L square equals to 4.

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Let's rewrite this equation so that it will look neater.

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To find L, we can see that since 4 is equals to L square, L can be found by calculating the square root of 4.

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Square root of 4 is 2. 

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Now this number has no meaning unless we include the unit for it.

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Since the area is given in square feet, the side of the square will be in feet.

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Therefore, the length of each side of the square is 2 ft.

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That is all for this lesson. Try out the practice question to further your understanding.

Practice Questions & More

Multiple Choice Questions (MCQ)

Now, let's try some MCQ questions to understand this lesson better.

You can start by going through the series of questions on the area of a square or pick your choice of question below.

Question 1 on finding the area of a square
Question 2 on finding the length of the sides of a square

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