You can define the length and angle of a line object with the numeric pad on your keyboard after you click to define the starting point. The NumLock must be on for this feature to work.
If you do not have a numeric pad, you can draw a line object with the mouse and modify the properties of the line with the Object Properties dialog box.
Do the following:
If the grid is activated, the line will snap to the nearest grid point if you enter a length that places the end point in between grid points. For example, if your grid points are 5 mm apart from each other and you enter a length of 24, Template Editor will snap the line’s end point to the nearest grid point. In other words, Template Editor rounds the line length up or down.