Final answer:
To find the area of the square garden, divide the perimeter by 4 to find the length of one side, and then square that length to find the area.
Step-by-step explanation:
To find the area of the square garden, we need to know the length of one of its sides. Since the garden is a square, all sides are equal. Let's call the length of one side x. The perimeter of a square is given by the formula P = 4x, where P is the perimeter and x is the length of one side. In this case, the perimeter is 84 ft., so we can write the equation 84 = 4x. To solve for x, we divide both sides of the equation by 4, resulting in x = 21 ft. Now that we know the length of one side, we can calculate the area of the garden using the formula A = x^2, where A is the area and x is the length of one side. Substituting the value of x, we get A = 21^2 = 441 square feet.
Learn more about Calculating the area of a square