0-9 and . (decimal)

Used to enter the length of the line you will draw. Decimals are allowed but snap-to-grid must be turned off.

' and " (feet and inches)

Used after 0-9 to specify feet or inches. Feet is used if neither is specified.

Arrow Keys

Used after 0-9 and ' or " to specify the direction the line should be drawn in. The arrow keys can also be used before 0-9 if there are already lines on the sketch, the cursor will automatically align with the closest point.

+ and -

Used after specifying a direction but before pressing Enter to arc the line.

Enter

Used to commit the current line and either start a new line or finish an area.

A (Auto-close)

If 2 or more lines have been draw and the area is not closed A will draw a line from the current point back to the starting point, completing the area.

Shift

Hold while drawing with the mouse to toggle snap-to-angle. See 'Using Shift & Ctrl To Affect Grid Behavior'.

Ctrl

Hold while drawing with the mouse to toggle snap-to-grid. See 'Using Shift & Ctrl To Affect Grid Behavior'.

Esc

Press to free the mouse from 'click -> click' or keyboard drawing.