Method that returns the moments of inertia about the centroid of the section.
| Name | Type | Description |
| Ixx | Double | Output Double that returns the XX partial moment. |
| Iyy | Double | Output Double that returns the YY partial moment. |
| Izz | Double | Output Double that returns the ZZ partial moment. |
| Ixy | Double | Output Double that returns the XY partial moment. |
| Iyz | Double | Output Double that returns the YZ partial moment. |
| Ixz | Double | Output Double that returns the XZ partial moment. |