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The perimeter of the rectangle below is 132 units. Find the length of side CD

The perimeter of the rectangle below is 132 units. Find the length of side CD-example-1
User MrQWERTY
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2 Answers

4 votes

The opposite sides of a rectangle will always be congruent. If they aren't, it's not a rectangle.

To find CD, you need to find what z is. This can be found using the given, the perimeter, and plugging that into the perimeter formula using the information given. You end up with 2(4z - 3) + 2(3z - 1) = 132. Solve for z and you find that z = 10.

CD is congruent to AB, which is 3z -1. Plug z in to get AB = 29. Since AB = CD, CD = 29.

User Ytbryan
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6.1k points
7 votes

The formula for the perimeter of a rectangle is

P = 2(L+W)

we are given the perimeter, and the length and width. we can plug everything we are given into the equation to solve for Z.

132 = 2[(4z-3) + (3z-1)]

132 = 2[ 7z-4]

132 = 14z-8

140=14z

10=z

now that we have the value of z, we can plug it in for the equation for line AB. line AB and line CD are the same since this is a rectangle

CD = 3z-1

CD = 3(10)-1

CD= 30-1

CD=29 units

hope this helped!

User Vathymut
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6.2k points