You can set the size and position of an object to an exact value using the Position and Size Dialog. This allows you enter dimensions and position for a single object in the same coordinate system shown on the rulers. You show the dialog by first selecting an object and then using the Position and Size command under the Arrange menu.
You can specify the left, top, right, and bottom of the shape in the units shown.
Changing the left and top values also changes the right and bottom, shifting them to maintain the same width and height.
The two radio buttons control whether changing the object's bottom or right value changes the object’s size (by leaving the left and top unchanged) or changes the object’s position (by changing the left and top to maintain the dimensions).