If you need to know how a database's disk space is allocated you can view a graphical representation via the Database file space visualizer.

From the Workspace select the database you wish to view details about, right click and select Database File Space from the Visualize menu.

Alternatively you can select Database File Space from the Visualize section of the Start page. This will display a dialog allowing you to select the desired database.

The visualizer shows 2 charts. The first illustrates used and unused space for each file group separated into data and transaction logs. The second chart illustrates the total amount of space allocated to data and transaction logs.

Additional information is presented in a tool tip when then mouse is hovered over a segment.