Anonymous
Anonymous asked in Education & ReferenceHomework Help · 1 year ago

# Finding dimensions of a rectangle?

The length of a rectangle is four times it’s width.

If the perimeter of a rectangle is 90cm

What is length and width

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• The perimeter of two of the sides, the length and the width, is 45cm.

We can divide this by five (4+1, because four of the width is the same as one of the length), and find the length.

We then multiply the length by 4 to get the width.

Width- 36cm

Length- 9cm.

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• P = 2(l + w)

But l = 4w

Substitute

P = 2(4w + w)

P = 2(5w)

P = 10w

90 = 10w

w = 9

Hence

l = 4 x 9 = 36

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• (l+b)*2=90

(4*b+b)*2=90

5b=45

b=9

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• Let x = the width

Then 4x is the length

The perimeter is than 2x + 8x or 10X

10x = 90 cm, so x = 9 cm. You can do the rest, at least I hope you can.

Algebra requires you to show all your work so I have done so.

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