Title function - lock aspect ratio?

[superspiffy]

In Premiere's Pro Title function, how do you lock the aspect ratios of your rectangles? The reason for this is that I want to make a rectangle template with a specified ratio so I can keep using it while only needing to resize it.

 

[Filmosity]

If you hold down the shift key while you click and drag, you'll be able to draw a perfect square. As for specific aspect ratios...I'm not entirely sure.