How to draw a straight line with precise length

[Dave R]

The Line tool will naturally snap to on-axis. You really shouldn't need to hold shift to draw a line on axis if you're going to type in its length anyway. The only time I would use Shift to lock a line on axis is if I'm using something else on the page for a reference for the end of the line. As in this GIF.

[Charlie__V]

Tip:
Don’t be afraid to “overdraw” the length of the line before entering the desired length. (often helps to show RGB axis/or highlight when parallel/perpendicular in “crowded” drawing)

IE: Draw line in desired direction (RGB axis/parallel/perpendicular to exisiting) approximately 20’ and enter 1’-8”

C

[pbacot]

I find the references come anyway and are easy to snap without shift, In fact so many references--some of which I don't think I'll ever figure out, some arcane trig relationships I guess.