> Resizing/Scaling a Clip
> To resize (or scale) a clip up or down, select the clip and then select any resize handle and drag your mouse. Hold the Shift key while scaling to preserve its aspect ratio. You can also use the scroll wheel plus the Command key to resize the selected clip.
> The scale of a clip is also specified as part of its properties. To adjust it in the video properties panel, select the clip and click the Video Properties tab. Use the Scale slider or manually enter a percent to resize the clip.