Question

A certain room is 10ft x 8ft x 9ft (L x W x H). How much would it cost to put adecorative trim around the perimeter of the room if the trim costs $2 per foot?$72

Answer 1

The perimeter of the room is given by the formula

$P=2L+2W$

we have

L=10 ft

W=8 ft

substitute

$\begin{gathered} P=2(10)+2(8) \\ P=36\text{ ft} \end{gathered}$

Multiply the perimeter by the trim cost ($2 per foot)

$\begin{gathered} total\text{ cost=36\lparen2\rparen} \\ total\text{ cost=}\ 72 \end{gathered}$