"Topics included in this chapter include centroids and how to locate them, moments of inertia, polar moments of inertia. products of inertia, parallel axis theorems, rotation of axes, and principal axes. Only plane areas are considered. A table of centroids and moments of inertia for a variety of common shapes is given...for convenient reference."

AXIS
AN IMAGINARY LINE THAT SERVES AS A CENTER OF ROTATION OR A REFERENCE LINE

CENTROID
A CENTER POINT OF A SHAPE

IRREGULAR BOUNDARIES
A BOUNDARY MADE UP OF UNUSUAL SHAPES AND FORMS, NOT PATTERNED AFTER SIMPLE GEOMETRIC SHAPES OR FORMS.

MOMENT
A FORCE APPLIED TO AN OBJECT AT SOME DISTANCE FROM THE ROTATION AXIS THAT MAY CAUSE THE OBJECT TO ROTATE. THIS IS THE SAME AS A TORQUE. THE MOMENT IS CALCULATED AS THE PRODUCT OF A FORCE TIMES THE DIRSTANCE OF ITS POINT OF APPLICATION FROM THE AXIS OF ROTATION.

SYMMETRIC ABOUT AN AXIS