# If the perimeter is 28 feet and the width is 4 feet, find the length of the rectangle.?

If the perimeter is 28 feet and the width is 4 feet, find the length of the rectangle.

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• A rectangle's perimeter is made up of two lengths and two widths, right? So we can write the formula for the perimeter as:

P = 2L + 2W

Sometimes you'll see this written as:

P = 2(L + W)

You are told the perimeter is 28 and the width is 4, so plug those in:

28 = 2(L + 4)

Divide both sides by 2:

14 = L + 4

Subtract 4 from both sides:

L = 14 - 4

L = 10

Double-check:

10 + 10 + 4 + 4 = 28

The length is 10 feet.

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• Anonymous
5 years ago

If the perimeter is 28 feet and the width is 4 feet, find the length of the rectangle.?

The perimeter of a rectangle is found by adding all the sides together (a rectangle has two lengths and two widths, thus four sides..)...so the formula for perimeter is:

P = l + l + w + w (where l is length and w is width..), combine like terms to get:

P = 2l + 2w <-- we are given P (perimeter) = 28 feet and w (width) = 4 feet...so..

28 = 2l + 2(4)

28 = 2l + 8

Now solve this linear equation, start by isolating 2l by subtracting 8 both sides (remember what you do to one side, you want to do to the other..), where 8 and -8 on the right side cancels out...

28 - 8 = 2l + 8 - 8

20 = 2l <-- now to isolate "l", divide both sides of the equation by 2...

20/2 = 2l/2

10 ft = l <--- answer...

So the length is 10 feet....

• No problem!

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• Perimeter =2(l+w) 28=2(l+4) 28=2l+8 2l=20. Length = 10

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• Rectangle length = L, width = W, perimeter, p, = 2(L+W).Now p = 28--> L+W = 14 and W = 4--> L = 10.

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• 28-2*4 = 2*length

20 = 2*length

10 = length

(units are feet)

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• 10 feet

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• P = 2L + 2W

28 = 2L + 8

L = 10 ft

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• 10 feet

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• 10 feet.

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• 10ft P=2x10 + 2x4 =20+8=28ft

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