The document discusses centroids and centers of gravity. A centroid is defined as the point at which an area is considered to be concentrated. Formulas can be used to find the center of gravity for simple and regular shapes. The document provides information on calculating centroids for irregular and regular shapes.

1. Center of Gravity & Centriod of areas
Centroid:
The centroids of an area may be defined as the point
at which the area is considered to be concentrated.

2. Centroid of irregular Shape:
We can find the laws of center of gravity of the simple area from the
formula
Centroid of regular Shapes: