This is how I do it most of the time:
If the wall/line is to be along a predefined Guide Line:
1) Click to start the wall/line.
2) Drag mouse in direction you want the wall/line to go and hold down SHIFT to lock in the angle.
3) While holding SHIFT, press 'R', this activates the Radius command in the Coordinates Palette, or activates the Distance command in the Tracker dialogue box.
4) Enter desired length of wall/line.
5) Press Enter/Return.
If the wall/line is NOT to be along a predefined Guide Line:
1) Click to start the wall/line.
2) Drag mouse in direction you want the wall/line to go and press 'A', this activates the angle command in the Coordinates Palette, or in the Tracker dialogue box.
3) Enter desired angle, ie 33. (Do NOT press enter at this time.)
4) Press 'R', this activates the Radius command in the Coordinates Palette, or activates the Distance command in the Tracker dialogue box.
5) Enter desired length of wall/line.
6) Press Enter/Return.
You can show the Coordinates Palette from the Window drop down menu, under Palettes.
You can turn the Tracker on/off in the Standard Toolbar, which is also turned on/off from the Window drop down menu, under Toolbars.
Hope this helped a little.
Mike