I'm having trouble explaining this. See attachment. Can someone help ? (Worried)

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- Nov 3rd 2009, 04:28 PMbbeam01Can you explain this ?
I'm having trouble explaining this. See attachment. Can someone help ? (Worried)

- Nov 3rd 2009, 04:43 PMadkinsjr
I'll call the first rectangle 'A' and the second 'B'.

For A, the perimeter is

$\displaystyle P_A=2w+2(2w+4)$

And for B:

$\displaystyle P_B=2(w+3)+2(3w-5)$

Do you see why that is? If so, then just plug in $\displaystyle w=5$, and see which perimeter is larger. To find out if there is a $\displaystyle w$ that would make the perimeters equal, just set $\displaystyle P_A=P_B$ and solve for $\displaystyle w$. - Nov 3rd 2009, 05:15 PMbbeam01
Thanks for the quick reply. I can solve for the perimeters of both rectangles but my problem is that this comes from my fourth-graders homework and I don't think they're actually trying to solve for the value of "w" but want the theory behind why they could or couldn't be equal. Could you please explain this ?

- Nov 3rd 2009, 06:27 PMbbeam01
Sorry, I understand now. Thank You for your help and your quick response to my question. (Clapping)