L: Length
W: Width
The perimeter of a rectangle is:
[tex]P=2W+2L[/tex][tex]\begin{gathered} P=2(3ft)+2(5ft) \\ P=6ft+10ft \\ P=16ft \end{gathered}[/tex]The area of a rectangle is:
[tex]A=W\cdot L[/tex][tex]\begin{gathered} A=3ft\cdot5ft \\ A=15ft^2 \end{gathered}[/tex]