Given:
The perimeter of a rectangle, P=168 in.
Let w be the width and l be the length of the rectangle.
The length of the rectangle is three times its width.
Therefore,
[tex]l=3w[/tex]Now, the perimeter of the reactnagle can be expressed as,
[tex]P=2(l+w)[/tex]Put l=3w and P=168 in the above equationa and solve for w.
[tex]\begin{gathered} 168=2(3w+w) \\ 168=2\times4w \\ 168=8w \\ \frac{168}{8}=w \\ 21=w \\ w=21\text{ in} \end{gathered}[/tex]Now, the length of the rectangle is,
[tex]\begin{gathered} l=3w \\ =3\times21 \\ =63\text{ in} \end{gathered}[/tex]Therefore, the length of the rectangle is 63 in and the width of the rectangle is 21 in.
