# Can you explain this ?

• Nov 3rd 2009, 04:28 PM
bbeam01
Can you explain this ?
I'm having trouble explaining this. See attachment. Can someone help ? (Worried)
• Nov 3rd 2009, 04:43 PM
Quote:

Originally Posted by bbeam01
I'm having trouble explaining this. See attachment. Can someone help ? (Worried)

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 PM
bbeam01
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 PM
bbeam01
Sorry, I understand now. Thank You for your help and your quick response to my question. (Clapping)