The force of attraction exerted by the earth on a solid body is known as Gravitational Force. It acts in a vertically downward direction and is known as weight of the body. Thus, the weight of the body is assumed to act at a point which is known as Centre of Gravity of a body. Copy the link given below and paste it in new browser window to get more information on The Centroidal Axis:- http://www.transtutors.com/homework-help/mechanical-engineering/bending-stress/moment-of-inertia-about-the-centroidal-axis1.aspx

2.  Introduction
 Some Important Definitions
 Centre of Gravity of Plane Figure
 Second Moment of Area
 Perpendicular Axis Theorem
 Parallel Axis Theorem

4.  Centre of Mass
 Centre of Gravity
 Centroid
 Centroidal Axis
 Axis of Reference
 Axis of Symmetry

7. Izz = Ixx + Iyy

8. IAB = IGG + Ah2

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