RegionCentroid

RegionCentroid[reg] gives the centroid of the region.

Examples

Centroid of a triangle:

RegionCentroid[Triangle[{{0, 0}, {1, 0}, {0, 1}}]]
(* {1/3, 1/3} *)

Centroid of a disk:

RegionCentroid[Disk[{2, 3}, 1]]
(* {2, 3} *)

Please visit the official Wolfram Language Reference for more details.