Answer:
13
Explanation:
It s given that Sam is placing rope lights around the edge of a circular patio with a diameter of 18 feet, thus

⇒

Now, circumference of the circular patio is given as:



Now, we know 1 ft=12 inches, therefore 56.52 feet=678.24 inches.

=

=

≈

Thus, 13 number of strands are needed to surround the patio edge.