The area of a square is given by , or . Take the square root of both sides to get .

The perimeter of a square is given by . Substitute the side length obtained from the area equation to get 

The perimeter of a shape is equal to the sum of the lengths of each side. By definition, a square has 4 equal sides. As a result, you can divde the perimeter by 4 to get the length of one side:

Since  divided by  equals , then  is the length of one side of the square.

You can also check your answer by adding up the lengths of all the sides or by multiplying the length of one of the sides by . If you get , you are correct.

The area of a square is calculated by multiplying one side by itself.

If the area is 25, then the length of one side will be the square root of 25.

The square root of 25 is 5, so each side must be 5 feet long.

If each of the four sides is 5 feet long, then the perimeter would be 20 feet because there are four sides total.

If a square has an area of 9 square inches, each side is 3 inches. This is because 3 inches times 3 inches is 9 inches. (The formula for the area of a square is length times hieght.)

Given that a square has 4 sides, we get the perimeter by multiplying 3 by 4, giving us a perimeter of 12 inches. 

For a square, all four sides are equal, and the area is calculated by multiplying one side by itself.

Since the area of the square is 36, we know that one side would be equal to 6 because .

Since each side is 6, the perimeter would be calculated by adding these four sides together.

This would give us:

Or

The perimeter of a square is equal to the sum of all of its sides.

If a side is , that means the perimeter would be equal to a value of , which is the equivalent of ; the correct answer. 

The area of a square is the product of one side times another side. Since the sides of a square are equal lengths, this is equal to:

Given that the area was 25 square feet, one side would be the square root of 25 (given that all sides of a square are equaly).

The square root of 25 is 5, which would be the length of one side. Since one side of the enclosure is the wall of Billy's home, Billy only had to build 3 additional sides, each of length 5.

Since 3 times 5 is 15, the correct answer is 15. 

When you have the area of a square, you can deduce the length of the sides by taking the square root of the area.

Given that the area is 100 square feet, and that the square root of 100 is 10, each side is 10 feet.

With 4 sides, that means that the perimeter of a square would be 4 times 10, which is 40.

The area of a square is given by , where is the sidelength.  

Plug in the given information:

Take the square root of both sides:

The perimeter of a square is given by , where is again the sidelength.  

Plug in the sidelength that we just calculated: