# Math Help - Can you explain this ?

1. ## Can you explain this ?

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

2. Originally Posted by bbeam01
I'm having trouble explaining this. See attachment. Can someone help ?
I'll call the first rectangle 'A' and the second 'B'.

For A, the perimeter is

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

And for B:

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

Do you see why that is? If so, then just plug in $w=5$, and see which perimeter is larger. To find out if there is a $w$ that would make the perimeters equal, just set $P_A=P_B$ and solve for $w$.

3. 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 ?

4. Sorry, I understand now. Thank You for your help and your quick response to my question.