Pivoting a line on one end point

Hey everyone,
Im just starting to learn the free version of sketchup and am having an issue with 2d lines. Ive learned how to draw a line and set it to my desired length, but cant seem to figure out how to pivot one end of the line around one fixed endpoint of the line without altering the length I had set, and need to remain constant. Can anyone help me figure this out? Thanks!


Have you selected the line and then tried using the Rotate tool?

Why exactly are you drawing a line that you will then need to rotate, anyway? I might make more sense to draw it in the desired orientation instead.

Im trying to get two lines of set length to meet. They are both fixed at length and each is set to another line on their opposing sides, so I need to be able to pivot the free end to where they would meet.

How about uploading your model so we can see exactly what you are trying to accomplish. I’d bet there’s a better way to do what you are after.

Where the top line and the line on the right side of the shape meet is what I’m trying to dial in.
I have hard dimensions for the top and right side lines, and have figured out how to make those lines the definite length that I need. Now I’m trying to figure out how I can pivot the two lines on the end where they should meet to find the spot where they will both meet without changing the length of the lines.

So you know the length of the diagonal line but you want it to meet the vertical line on the right?

You could use the Pie tool.

Start with this. You really don’t need the horizontal line shown in blue. You can just art the Pie tool and type in the length of that line as the radius.

Get the Pie tool and draw the shape so it meets the vertical line.

You’ll get a face when you do it correctly.

Erase the unneeded bits.

The problem I’m having is that the bottom right corner is not a 90 degree angle, and I’m not sure exactly what the angle is. I need a way to pivot the top and side vertical until the ends meet up exactly, without changing the lengths of the line. So, the point where they meet is only determined by the lengths of the lines.
Seems like there should be some way to just click the end of the line and pivot it on the other connecting end.

You keep adding more little details that weren’t there before.

This could be more easily solved with certain extensions in the desktop versions of SketchUp but to do it in the free version, I think you’ll need to do some trig.

Ah. I was afraid of that. I really appreciate your help.

It isn’t difficult. Since you have the left and bottom dimensions, you can find the length of the diagonal.

And with the length of the diagonal along with the top and right sides, you can calculate the angles.

Isn’t it just two arcs with the pie tool and join the dots where they intersect.

any SU version without trig or extensions…


But make those edges exact lengths.

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Is what you’re doing there possible with the free browser version?

A bit touchy to get the top and right to come out as exact required values…

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Unless you get lucky and the intersection happens to lie on vertices of both arcs, no.

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I did, they are exactly the length I was wanting :wink:

any version, they are standard tools…

‘Dimension Tool’, ‘Move Tool’, ‘Rotate Tool’ …

the ‘model units’ are set to many decimals to make it more accurate…


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And a wizard is never late. :wink:

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For the edification of those who don’t already know (if you already know or don’t care, skip to another topic :wink:):

If you wanted to solve a problem like this using pencil and paper, you would draw the bottom and left sides, swing arcs of the required radii with a compass from their endpoints, and draw the lines to the point where the arcs cross.

In SketchUp the analagous process isn’t reliable because SketchUp represents an arc as a sequence of straight segments. Only the endpoints of these segments are at the target radius of the arc. So, only if endpoints from both arcs just happen to land at the same place will their crossing point in SketchUp be the exact answer (a very remote likelihood). There are several extensions for the desktop version of SketchUp that address this exact problem, but extensions are not yet possible for the web version.

The process @DaveR showed works because he ended the arc on the target line, and the end of an arc (like all its vertices) is at the exact radius. But you can’t do this when both lines can be pivoted.

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That did it! Thanks John!