A really stupid question..... (perpendicular lines)

[iainlines]

Forgive my ignorance....

Lets say there is a line across my screen and I want to draw another line snapped to it and 90 degrees to it. How? Without measuring the angle of the first line, which is not at zero or 90 degrees. In 12 years I've never known this:oops:

[JD Mather]

Perpendicular snap

or

Perpendicular Constraint in 2011 and later

or

copy rotate 90°

or... probably at least half a dozen other ways.

[iainlines]

With perp snap it seems a bit hit and miss in that I snap to the line, hover over the snap symbol and it SOMETIMES gives me the option to draw perpendicular to the first line and sometimes not

[nestly]

That would be the Perpendicular OSnap.

 

Select it from the OSnap Toolbar -or-

Use Shift + Right click to activate the OSnap menu -or-

Type PERP at the command line when AutoCAD is prompting for a pick point -or-

Enable PERP in OSnap settings (DSETTINGS)

 

[rkent]

Draw a line perpendicular to the endpoint of a line.

 

1. OTRACKING on,OSNAP endp and perp set, POLAR on, start line command,

acquire end point, move 90 degrees in direction you want, type the

value or pick, pick the point you first acquired.

 

2. Rotate the UCS with the OBject option, and draw away. I have this

automated with UO as my quick keys (UCS, OBject), and to go back I use

UW (UCS, World).

 

3. With POLAR set to Relative to last point, start the line command,

use an osnap, pick the line, move 90 degrees in the direction you

want to draw and enter

the value or pick.

 

4. Rotate the crosshairs with snap, rotate, pick two points on the

line, ... This is also easily automated with a lisp so you can pick

the line and have the crosshairs rotate.

 

I am sure there are others.

 

I only use #2 as I don't have those other settings set and ready to go so it is easier to type UO, pick object, and start drawing.

[ReMark]

Is there other geometry involved that will be either perpendicular or perhaps parallel to the angled line as well?

[fuccaro]

I adjusted the thread title to reflect the content.

[iainlines]

Thanks all. Nestly, that sorted it, cheers! :-)