See this video if you're using V9 which explains the various ways to use the drawing tools - http://support.vectric.com/tutorials/V9 ... ideo_id=16
For your specific example pick your start point and click. Then enter the angle and distance in the dialogue box and click add. Press the spacebar or click finish to exit drawing.
Or with V9 you can type the values directly without having to use the dialog box. Click to start as previously then type, for example, 45A100L to create a line at 45 degrees 100 units long.