WPF dynamic layout: how to enforce square proportions (width equals height)?

Question

I\'m learning WPF and can\'t figure out how to enfore my buttons to take a square shape.

Here is my XAML Markup:

Answer 1

@Dan Pruzey's answer was good, but did not shrink the square if the window was downsized. What I found to work best was to set the height to auto and the width to that height:

This kept the button a square when sizing my window bigger and smaller. Hope this helps someone.