All right... for a moment think that the semi-circles are not semicircles, but they're actually full/whole circles. Then find the circumference of all the circles. Since there are two circles with a diameter of 8, we can double the circumference of one, and boom-chika-bam... you already have the circumference for two circles. Don't understand... see...
Circumference of one 8 in. diameter circle:
in.
Circumference of a circle with three inch radius:
in.
(
means times!) Now... half the circumference of both of the circles...
One 8-in. diameter circle cut in calf: 25.12 ÷ 2= 12.56
One 3-in.-radius circle cut in half: 28.26 ÷ 2= 14.13
Now just add to get the length of the rope!
12.56 + 14.13 + 12.56 <= There are two 8-in "ones", you add 12.56 two times!
= 39.25 in.
The rope is 39.25 inches long!