In the parallelogram above, length is 20 cm, width is 13 cm, and height is 14 cm. A parallelogram with which of the following dimensions would have the same perimeter?
A. length = 9 cm, width = 25 cm, height = 13 cm
B. length = 20 cm, width = 25 cm, height = 15 cm
C. length = 8 cm, width = 25 cm, height = 13 cm
D. length = 8 cm, width = 13 cm, height = 14 cm

Question

In the parallelogram above, length is 20 cm, width is 13 cm, and height is 14 cm. A parallelogram with which of the following dimensions would have the same perimeter?
	A. 	 length = 9 cm, width = 25 cm, height = 13 cm
	B. 	 length = 20 cm, width = 25 cm, height = 15 cm
	C. 	 length = 8 cm, width = 25 cm, height = 13 cm
	D. 	 length = 8 cm, width = 13 cm, height = 14 cm

anonymous · Answer

attachment

e.mccormick · Answer

The key here is realizing which numbers matter to the perimeter.  Do you know which two?

anonymous · Answer

l and h, right?

anonymous · Answer

er. those arent numbers .~. but you understand

e.mccormick · Answer

Height if a paralllogram is used for area, not perimeter.

e.mccormick · Answer

So the perimeter is 2L+2W.  Once you know that for the given parallelogram, you can see which of the choices matches it.

anonymous · Answer

so it'd be something like ermm.. 68?

e.mccormick · Answer

Exactly 68.  So which of the 4 also has 68?

anonymous · Answer

none of them seem right! I devided l and w by 2 and added them in each of the four choices and none of them add up to 68! >_<

anonymous · Answer

*multiplied, not devided

e.mccormick · Answer

Eh?  Same formula.  2L+2W=68.  Any that has that same result is the answer.
A. length = 9 cm, width = 25 cm, height = 13 cm 
B. length = 20 cm, width = 25 cm, height = 15 cm 
C. length = 8 cm, width = 25 cm, height = 13 cm 
D. length = 8 cm, width = 13 cm, height = 14 cm

So:
A=2(9)+2(25)
B=2(20)+2(25)
C=2(8)+2(25)
D=2(8)+2(13)

e.mccormick · Answer

B is waaaaaaa of at 40+50=90.  That is nowhere near 68.

anonymous · Answer

c and d are the closest but still not exact >_<

e.mccormick · Answer

Well, not the closest.... there is one closer.

jim_thompson5910 · Answer

The height isn't used in the perimeter, only the length and width

P = 2L + 2W

P = 2*20 + 2*13

P = 40 + 26

P = 66

So the perimeter of the original parallelogram is 66 units

anonymous · Answer

if b isnt it, how is a right? i keep getting 86 .~.

anonymous · Answer

whaaat? its 66 instead of 68?

e.mccormick · Answer

Oops!  Missed that misake!  LOL.  Yah.  66.

anonymous · Answer

omg okay cx  so its c then!

jim_thompson5910 · Answer

yep, I'm getting C as well

e.mccormick · Answer

I made the same slipup myself!  I added it right but read what she had wrong.  Thanks for catching it! @jim_thompson5910

jim_thompson5910 · Answer

np, happens to me all the time too

e.mccormick · Answer

Yah, it is C.  Doh!  Sorry for the confusion.

anonymous · Answer

THANKS SO MUCH YOU GUYS!^__^

jim_thompson5910 · Answer

you're welcome