To make controls the same size:
Using the <Shift> key method (described in Selecting Controls), select two or more controls.
Select Make Same Size from the Options menu.
On the secondary menu, select one of the two options:
Make Same Size Width reduces or increases the width of the second and subsequently selected controls so that they are the same width as the first selected control, for example:
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Make Same Size Height reduces or increases the height of the second and subsequently selected controls so that they are the same height as the first selected control, for example:

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An alternative to using the menu is to press <Alt+→> to make controls the same width or <Alt+↓> to make them the same height.