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he perimeter of parallelogram ABCD is 80 cm. AD is 7 cm more than twice AB. Find the lengths of all four sides of ABCD.

User Andymel
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1 Answer

12 votes

Answer:

AB = 11

BC = 29

DC = 11

AD = 29

Explanation:

First, draw out and label the parallelogram ABCD. I've done so for you below:

Now, to figure out what to label the sides, refer to:

AD is 7 more than twice AB.

"Than" means that whatever we write, we flip it. For example, 7 more then 5 would be 5+7. Though this may not be important for addition, it is for subtraction. For example, 7 less than 5. This would be 5-7, but if you wrote it wrong, it would be 7-5.

"Is" is key word for "=". So:

AD = 7 more than twice AB.

"Twice" means "two times." So:

AD = 7 more than 2(AB).

AD = 2(AB) + 7

Let's label AB as x.

If the perimeter is 80, then that means AD+AB+BC+DC=80.

We know that in a parallelogram, opposite sides are congruent. So:

AD+AD+AB+AB=80

(2x+7) + (2x+7) + x + x = 80

2(2x+7) +2x = 80

4x + 14 + 2x = 80

6x + 14 = 80

6x = 66

x = 11

AB = 11

AD = 2x + 7

= 2(11) + 7

= 22 + 7

= 29

he perimeter of parallelogram ABCD is 80 cm. AD is 7 cm more than twice AB. Find the-example-1
User Ewulff
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5.6k points