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Anyhow, I'm trying to calculate the mass moment of inertia for a flat, triangle-shaped plate. The axis of rotation goes through the center of mass of the plate, and is parallel to the Z axis if the vertices of the triangle are defined on the X and Y axes. According to:

http://www.efunda.com/math/areas/triangle.cfm

the formula for this is

http://www.efunda.com/math/areas/images/triangle12.gif .

Now, this is assuming that the area density is equal to 1. If I want to find the actual mass moment of inertia of the triangle, and I know the area density, would I just multiply the final result by the area density? I'm skeptical that it's that simple. Would I need to isolate the formula for the are of a triangle out of that equation, multiply it by the area density coefficient, and then plug that back into the equation by working backwards (if that even makes sense :| )?

Any help is really appreciated!

Peace and love,

dgm

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# Homework Help: Moment of inertia & area density

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