**Straight Line:** The centroid of a
straight line is located at its midpoint.
However, for a shape made up of multiple
straight-line segments, its centroidal location can be found as

(1) |

where x_{i} y_{i} z_{i} represent the
centroidal coordinates of the i^{th} line segment.
In applying Eq. (1), we are free
to choose any reference coordinate system that simplifies the calculation of the centroid.
Using the moment-of-a-force analogy, the numerator in Eq. (1) represents the sum of "moments" produced by the individual
line segments, and the denominator represents the total line length.