You can resize an element by dragging its handles or typing exact dimensions
Here are ways to resize elements:
To resize an element by dragging, select the element and the drag one of its selection handles. To resize an element in one dimension, drag a side handle instead of a corner handle.
To maintain an element's proportions, hold down the [Shift] key as you drag.
To resize an element using exact proportions, select the element, click Inspector in the toolbar, click the Metrics button, and then use the Width and Height controls.
To resize several elements at once, select the elements, click the Metrics button, and then type new values in the the Width and Height fields.
To resize a panel independently of its contents, hold down the [Option](Mac) or [Alt](Win) key while dragging the selection handles.
To resize a cluster elements so that they maintain their relative positions: