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A rectangular garden must have a perimeter of 160 feet and an area of at least 1300 square feet. Describe the possible lengths of the garden. Round your answers to the nearest foot.

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User DerKorb
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1 Answer

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Answer: The lengths of the garden are 57.32 feet and 22.68 feet (approximately)

Step-by-step explanation: The area has been given as 1300 which means,

Area = L x W

1300 = L x W ———(1)

Also the perimeter has been given as 160, hence we also have

Perimeter = 2(L + W)

160 = 2(L + W)

80 = L + W ———(2)

From equation (2), make L the subject of the equation

L = 80 - W

Substitute for the value of L into equation (1)

1300 = L x W

1300 = (80 - W) x W

1300 = 80W - W^2

Rearranging the equation we now have;

W^2 - 80W + 1300 = 0

Since we cannot factorize we shall apply the quadratic equation formula to solve for W. Please refer to the attachment for details of this.

Having calculated the value of W to be either 57.32 or 22.68, we can now find the value of L as follows;

Substitute for the value of W into equation (1)

1300 = L x W

1300 = L x 57.32

Divide both sides of the equation by 57.32

22.68 = L.

(Note that if we take the other value of W which is 22.68, the value of L shall be 57.32)

Since the area of the rectangular garden must be AT LEAST 1300 square feet we shall use the exact values for;

Length = 57.32 feet

Width = 22.68 feet

A rectangular garden must have a perimeter of 160 feet and an area of at least 1300 square-example-1
User Riccardo Marotti
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