Sam is placing rope lights around the edge of a circular patio with a diameter of 18 feet. the lights come in lengths of 54 inches.how many strands of lights does he need to surround the patio edge?

You can find the circumference of the circle with the circumference equals 2pir.
circumference=2pi9
circumference=18pi
circumference=56.55 feet
you can then turn the feet into inches by multiplying by 12
(56.55 feet)x(12inches/foot)=678.58 inches
then divide 678.58 inches by 54 inches to find how many light strands are needed.
(678.58 inches)/(54 inches/strand)=12.57 strands

I think you just have to find the degree angle for each letter