perimeter

[eddy2017]

Hi, I would like confirmation of what i did here in this problem.
the perimeter of a rectangular playground is 46 meters. If the length of the park is 7 meters, what is the width of the park?.
My answer:
Given.
perimeter=46 meters
length=7 meters
Width=? (let width be w)

Formula to find the perimeter of a rectangle=

P=2(l*w)
46=2(7*w)
46=14+2w
46=16w (divide 16 into both sides)
46 =16w
16 16
w=2.88

I am looking forward to your confirmation.
Thanks in advace,
eddy

 

[Deleted member 4993]

Hi, I would like confirmation of what i did here in this problem.
the perimeter of a rectangular playground is 46 meters. If the length of the park is 7 meters, what is the width of the park?.
My answer:
Given.
perimeter=46 meters
length=7 meters
Width=? (let width be w)

Formula to find the perimeter of a rectangle=

P=2(l*w)
46=2(7*w)
46=14+2w
46=16w (divide 16 into both sides)
46 =16w
16 16
w=2.88

I am looking forward to your confirmation.
Thanks in advace,
eddy

Formula to find the perimeter of a rectangle=

P=2(l*w)........................................................Incorrect
46=2(7*w)....................................Correct( follows from line above)
46=14+2w....................................Correct ( but does not follow from line above)
46=16w (divide 16 into both sides)................................................Incorrect - You CANNOT simply add 14 + 2w

P=2(l*w)........................................................Incorrect
46=2(7*w)....................................Correct( follows from line above)
46=14+2w....................................Correct ( but does not follow from line above)
.................continuing from here

46 - 14 = 14 + 2*w - 14

32 = 2*w

32/2 = 2*w/2

16 = w

 

[lev888]

Hi, I would like confirmation of what i did here in this problem.
the perimeter of a rectangular playground is 46 meters. If the length of the park is 7 meters, what is the width of the park?.
My answer:
Given.
perimeter=46 meters
length=7 meters
Width=? (let width be w)

Formula to find the perimeter of a rectangle=

P=2(l*w)
46=2(7*w)
46=14+2w
46=16w (divide 16 into both sides)
46 =16w
16 16
w=2.88

I am looking forward to your confirmation.
Thanks in advace,
eddy

You switch from multiplication to addition along the way, what's that about? What's the formula for the perimeter of a rectangle?

 

[eddy2017]

Formula to find the perimeter of a rectangle=

P=2(l*w).....................................Correct
46=2(7*w)....................................Correct
46=14+2w....................................Correct
46=16w (divide 16 into both sides)................................................Incorrect - You CANNOT simply add 14 + 2w

P=2(l*w).....................................Correct
46=2(7*w)....................................Correct
46=14+2w....................................Correct

46 - 14 = 14 + 2*w - 14

32 = 2*w

32/2 = 2*w/2

16 = w

Thank you so much!!!.

 

[eddy2017]

You switch from multiplication to addition along the way, what's that about? What's the formula for the perimeter of a rectangle?

Yes, big mistake, thank you. I understood now.

 

[Deleted member 4993]

Formula to find the perimeter of a rectangle=

P=2(l*w).....................................Incorrect
46=2(7*w)....................................Correct (follows from the line above)
46=14+2w....................................Correct (but does not follow from the line above)
46=16w (divide 16 into both sides)................................................Incorrect - You CANNOT simply add 14 + 2w

P=2(l*w).....................................Correct
46=2(7*w)....................................Correct
46=14+2w....................................Correct .................continuing from here

46 - 14 = 14 + 2*w - 14

32 = 2*w

32/2 = 2*w/2

16 = w

I missed one other BIG problem. Your equation for perimeter was incorrect. But in the 3 rd line you have used the correct equation. So final production:

P = 2 * (l + w)

46 = 2 * (7 + w)

46/2 = 2 * (7 + w)/2

23 = 7 + w

23 - 7 = 7 + w - 7

16 = w

 

[eddy2017]

I missed one other BIG problem. Your equation perimeter was incorrect. But in the 3 rd line you have used the correct equation. So final production:

P = 2 * (l + w)

46 = 2 * (7 + w)

46/2 = 2 * (7 + w)/2

23 = 7 + w

23 - 7 = 7 + w - 7

16 = w

Great, thank you Khan.

 

[Steven G]

I prefer to use what I call half perimeter.

Half the perimeter is 23 and L+W
L+ W = 23
7 + W = 23
W = 16