Calculating Moment of Inertia for Square Particle System

[duplaimp]

Homework Statement

There are four masses (particles) with a mass of 30gr each and they are at the vertices of a square that has each side with a length of 90cm.
What is the moment of inertia of this system through a perpendicular axis that is at the center of the square?

The Attempt at a Solution

My idea is to use the moment of inertia $I = mr^{2}$ (Point mass m at a distance r from the axis of rotation.)
Then the distance will be the hypotenuse of a right triangle that has each side with 45cm and putting that into the moment of inertia and multiply by 4

Is this correct?

 

[Filip Larsen]

Yes, that is correct.

 

[duplaimp]

Thank you