Jump to content

How to define a point (visible and snapable one)?


Recommended Posts

Posted (edited)

I want to define a point (U in the following drawing) and use it as a reflection point to find the reflection of vertices of a triangle regarding this point.

 

I know there is "point" command and I can define a point with this command.

 

Upon defining the point, I can't see it in the monitor and I can't snap it to draw the line.

 

How can I make it visible and apply snap to point?

 

My main issue is as follows: In the triangle ABC and point U are given, points A', B' and C' are reflection of points A,B and C according to point U. What is the easiest way to obtain points A', B; and C' and draw the polygon?

 

I do as follow although might not be a smart way:

In order to find the reflection point, I want to draw a circle with center located in this point (U), and radius is known (AU, Bu and CU), then draw the ray from A, B and C passing through point U and then trim the ray. If you have better solution for finding the reflex, please let me know.

Reflection is same as mirror but my object is an imaginary point (A, B and C) and I don't know if I can apply the mirror command in this case.

1.jpg

reflection.dwg

Edited by khoshravan
Posted
. . . .

What is the easiest way to obtain points A', B; and C' and draw the polygon?

. . . .

 

 

I think if you placed points at A, B, C, and U then you could just rotate A, B, and C 180 degrees around U. The ROTATE command has a COPY option to keep the original locations intact.

Posted

 

Thanks. It looks that size of point marker (ddptype) has two options, relative to screen and absolute. Thanks again.

Posted
I think if you placed points at A, B, C, and U then you could just rotate A, B, and C 180 degrees around U. The ROTATE command has a COPY option to keep the original locations intact.

 

Very clever point:thumbsup:. I have focused on the problem solving and was totally unaware of this simple point. Thanks a lot.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...