#### Answer

(a) $56.5~ft$
(b) 10 strips
(c) $155.40

#### Work Step by Step

(a) We can find the circumference:
$C = \pi~d = (\pi)(18~ft) = 56.5~ft$
(b) We can find the required number of strips:
$\frac{56.5~ft}{6~ft} = 9.4$
Since the strips are sold in lengths of 6 feet, we need to buy 10 strips.
(c) We can find the cost:
$cost = (\$2.59/ft)(10)(6~ft) = \$155.40$