Select "Box" mode from the toolbar. Choose a layer from the layer panel in which to create a new box. Left click at the first point, move the mouse to the second point and finish the box by left-clicking at the second point. Press the ESC key to cancel the operation.
While you drag the box, two edit boxes are shown at the top of the layout view. Press the Tab key to enter these edit boxes. Use the Tab and Shift+Tab keys to navigate between the boxes. You can specify numerical values for the box width and height here. Pressing the Enter key will apply these dimensions. Pressing the Escape key will leave the edit fields.
Note: A box, once created, will remain a box. For example, it is not possible to delete one vertex of it, thus forming a triangle. This is only possible for polygons.