Move corner of a 2D triangle, how to 2012

[Anonymous]

Dummy newbie question, sorry...

I know the an angle and two sides of an irregualr trangle.  I used the line command to draw the first side, polar coordinantes to draw the second side at the specified angle, and then let the line command close the figure.  Later I noticed that I incorrectly inputted the length of the second side.

I need to change the length of the second side, keeping the first side and angle unchanged.  I see one, and only 1, corner is in the wrong place -- it just needs to move down the existing second side until the second side is the correct length.

No matter what I've moved, stretched, lengthened, trimed, the whole entire three sided figure changes.  I can'd find the command I need!  It's like Acad is always operating on all three side, even though I just want to work with the one.

What I want to do is shorten one side of a triangle to an exact length, moving one vertex (and implicitly the other side attached to it) while leaving the third side (and other two verticies) exactly where they are.

Please help, and Thanks!

[dgorsman · Accepted solution]

It may have been auto-constrained when you drew it.  That would keep all sides in relative position.

[nestly2]

I does sort of sound like a constraint issue, but I don't think the normal auto-constraints for 3 connected line segments would cause all 3 lines to move together when using commands like STRETCH, LENthen, TRim, etc. 

Did you try using GRIPS?  see below

Can you attach your drawing here so we can have a look?

[Anonymous]

Thank you for the ideas.

Researching, will update.

[Anonymous]

Your're right, my problem triange is constrained up the ying-yang.

1.  It would be nice if there was an easy way to suspend constraints for just one action, like setting (or unsetting) a snap while placing a point.

2.  I swear there are times when not all of my constraints are showing, even after I showall on the paramaterization menu.

There's like 1 "contrained" graphics on the screen (which contains several items), even after I even successfully added another constraint.  The constraint icon just doesn't show.  I know the constraint is there, because when I delete a constrained item, I get a message about the (unshown) constraint being deleted too.

Are there more than one general kind of constraint?

[Anonymous]

Neat graphic!

Didn't notice the animation at first because I keep gif animation turned off.

Grips have the same problem.

[nestly2]

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Jared_Techie wrote:

2.  I swear there are times when not all of my constraints are showing, even after I showall on the paramaterization menu.

Are there more than one general kind of constraint?

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 2)  You're not imagining it,

Yes, there are Geometric Constraints (display controlled by CONSTRAINTBAR sysvar) and Dimensional constraints (display controlled by DCDISPLAY sysvar), but in the animation below, they're all "Geometric" and some still remain hidden.

[Anonymous]

I wonder if the missing constraint icons have been gone so for so long it has advanced from the "bug" list to the "fee-chure" list! <grin> <humor>

Thanks!