four pencils are held together in a square by an elastic band if the pencils are of diameter 7mm what is the length of the band in this position
49.99114858
The distance between pencil centers on each side is 1 diameter, or 7mm.
At each corner there is a quarter-circle, so the entire length is
4*7 + π*7 = 7(4+π) mm
The number of pencils touching the band is 6 using 60° for ©
2r+[©/360×2#r]
That is perimeter if a sector.