# Moment of inertia of a disk

## Homework Statement

What is the moment of inertia of an 8 kg, 40 cm diameter disk for rotation through the edge of the disk?

## Homework Equations

$$I = \frac{1}{2}MR^2$$

## The Attempt at a Solution

Inertia at the center of the disk would be $$I = \frac{1}{2}MR^2$$, right? I'm not sure what the right equation for inertia at a point on the edge of a disk would be.

$$I = I_{cm} + Md^2$$