(Optional) If you want to dimension the first end point of the axis, press
Shift and hover the mouse over a line or point to
create a dimension relative to that line or point.
Click or press Enter to set the first end point of the
axis.
Click or press Enter to set the other end point of the
axis.By default, the axis is dimensioned to its first end point. You
can also press Shift and hover the mouse over another
line or point to create a dimension relative to that line or point.