How to Find the Components of the Inertia Tensor Matrix for Point Masses?

[lulamuz27]

Homework Statement

Hi everyone, I need some help to know how to find the components of the inertia tensor matrix of a rigid body formed by a gruop of point masses attached to bars with no mass.
I have 3 masses with cartesian coordenates: 1 (a,a,0), 2 (a,0,0) and 3 (-a,-a-0).

The Attempt at a Solution

The book says: Ixx= 2ma^2, Ixy= -2ma^2, why??


Thank you!

 

[ZetaOfThree]

Welcome to PF!
Do you know the general formulas for the elements of the inertia tensor? That would be a good place to start.