The diameter of the smaller pipe is 4″

The diameter of the larger pipe is 12″

Now you are going to need your conversion factor to convert sq. mil to cir. mil. which is 0.748 if memiry serves me right. because it is not squared off at the edges it is round.so you are going to need only 0.748 of 4″ and 0.748 of 12″

.748 * 4 = 2.992 or 3″

.748 * 12 = 8.97 or 9″

now add them all up.

16+3+9= 28″ of wire.

Might should double check me on conversion factor pretty sure it is 0.748 but could be wrong on that.

so…

big pipe’s half circumfrence = 2 x 6 x 3.14 / 2 = 18.84

small pipe’s half = 2 x 2 x 3.14 / 2 = 6.28

the straight line needs a right triangle. draw a line from the spot where the wire touches the big pipe straight to the right, and a line from where the wire touches the small pipe straight up to form a right angle triangle.

using the radii, you see that the triangle is 8 in long (6 + 2), and 4 in tall (6 – 2).

length of straight wire = the square root of (8 x 8) + (4 x 4), or 8.94

so…

8.94 + 8.94 + 18.84 + 6.28 =

43 inches.