two simple questions for autocad

hi guys, I am an autocad beginner and I have two questions

1. is there possible to draw a line on a line at certain distance?

For example I have a 10 meters line and i want to draw a new line on it at 3 meter location

2. about moving object, the question is like if you draw a circle and you want to move the circle to a position which will connect with 2 lines(the lines remain the same position,not moving). its hard for me cuz i can only move and connect the circle with one line and then i get stuck cuz i have no idea how to move the circle to connect with the other line.

sorry about my language if it confuses you.

1. Start the LINE command. Before picking your start point, enter TK (for TracKing). Now pick the end point of the line, go 3 meters with the cursor and pick the next point. Then press enter to stop tracking, then start drawing the line from the 3 meter location. (Ok, your crosshairs need to be set to the same angle as the line for this to work, but SNAPANG makes that easy). 1A. Draw a 3 meter circle from the endpoint of the line, start your new line at the INT of the circle and the line. Erase the circle when you're done.

2. If I understand you correctly, then don't move the existing circle, just draw a new circle using the TTR option

Thank you rkmcswain, the first question is solved by using the TK command. Its awesome.

But for my 2nd question , actually it happened in my interview. In that interview I need to insert a block( which is a circle) to connect the two lines on a design graph, those two lines are fixed. So I cant move or change them. So what i did was I connect the circle with one line and then try to rotate the circle to connect with other,

but unfortunately it was impossible

EDIT: Based on your above reply, seems like you wanted a simpler task accomplished, but at least the following might be usefull.

Most of this, RKM has covered, but I must assume that you don't necessarily want to start your new line right at one of the end points of your existing line. this looks long but once you have done it a couple of times, it only takes a split second, or so;).

Turn off Ortho Mode, Turn on Polar tracking. Turn on Auto Snap tracking. Turn on Dynamic Input. "F1 them, I don't remember the variable names right at the moment. If your existing line is not at 0 deg. or 90 deg., or even if the existing line is at one or the other, turn on snap angle (snapang).

Now start the Line command.

Only HOVER at one end point of your existing line. Now begin to move your cursor along the existing line (or actually in any direction). A tracking vector and a little 'x' should appear behind and with your cursor as you move it.

If the vector line does not appear, then make sure you have turned off Ortho Mode, and turned on Polar tracking mode.

Now with the little 'x' as close as possible to RIGHT ON TOP of (snapang helps) your existing line, simply type in your desired distance, say 3m. AutoCAD will start you a line segment 3m from the grip where you acquired your "Tracking Vector".

Then move the cursor away in the direction you wish your line to go, whether you wish to follow the existing line or go somewhere else with the second point, and type in the distance for your line length. Bingo, another line, exactly as long as you need, exactly where you wanted it to be.

The thing is, with the correct set of environmental and/or drafting options set up, AutoCAD will move a distance and direction you indicate, away from an acquired base point and then either start your object, or set its midpoint, or finish it. There is no need to be squinting at the little angle and distance windows next to the cursor and getting a twitch in your wrist trying to manually get the length and angles correct. The program will do it for you.

In that interview I need to insert a block( which is a circle) to connect the two lines on a design graph, those two lines are fixed. ...

Can you attach a file with something similar to what you recall?

I think I know the question as I give this to my students - but I want to see your version of recall. (you will kick yourself when you see how easy the solution is)

so here is the attachment,

Basically there are two graphs, first one is a circle connected with two lines.

Then I copied and deleted the circle, so there are two lines remind.

So you can just use the circle in first graph to create a new block and then try to insert block for second graph to make it looks like the first one . Which I dont know how to do it.....

Drawing3.dwg

I posted my attachment. Thanks for helping

what I did is insert the block, I choose one point on the circle to be my basepoint, then I connect the basepoint with the end point of one line.

So the circle connect with one line, but I have no clue how to connect to the second the line. Thanks for the tips Dana W told me, but it does not work for my case.....

Thanks a lot for your guys so far.

I knew my language is horrible but thanks a lot for you guys have done for me

Rotate > [R]eference

*edit* Incorrect image removed

I tried you way, but the question is, when I rotate the circle.(the circle connect with one line as you did) and then I click reference, I choose the end point of the line connected with the circle and the intersection point of the circle with other line. And then I click the end point of the other line to rotate the circle.

They are not perfectly math. which means the circle does not connect with the other line. I dont know why . am i doing wrong for some steps?

Perhaps another way of placing your circle is to first of all draw two temporary circles of the same radius ( 0.38 ) at the ends of the two lines. Then your circle centre point is where these two circles intersect.

As you can see there are many ways of achieving the same outcome.

Perhaps another way of placing your circle is to first of all draw two temporary circles of the same radius ( 0.38 ) at the ends of the two lines. Then your circle centre point is where these two circles intersect.

 

As you can see there are many ways of achieving the same outcome.

I am a big fan of geometric solutions myself.

After using nestly's very succinct approach you may need to REGEN,

in order for the resulting geometry to display properly.

Regen is your friend.

Remember this. It may not solve all problems but it is still a great tip to remember. 're' is the same command, but with less typing.

OK, now that I see where the lines are, I like Eldon's solution. I could not open the drawing, so I was stuck with my assumption that the lines were on opposite sides of the circle.

I tried you way, but the question is, when I rotate the circle.(the circle connect with one line as you did) and then I click reference, I choose the end point of the line connected with the circle and the intersection point of the circle with other line. And then I click the end point of the other line to rotate the circle.

They are not perfectly math. which means the circle does not connect with the other line. I dont know why . am i doing wrong for some steps?

Ooops.. you are correct, In my haste, I missed an important step.

Perhaps another way of placing your circle is to first of all draw two temporary circles of the same radius ( 0.38 ) at the ends of the two lines. Then your circle centre point is where these two circles intersect.

 

As you can see there are many ways of achieving the same outcome.

I'd go with simple too, but just use the copy command, copy the circle using it's center point, 1st copy goes to the end of one line, 2nd copy goes to the end of the second line, and then 3rd copy goes at the point where the first two circle cross, then delete the 2 circles that are not needed.

Thank you so much guys, the way eldon and steven-g said are the same and its simple. also thank you nestly, I got how the reference command works.