Finding a point position on a shape after the shape was rotated

Hi. First I'd like to let you know that I'm probably in the wrong section, but this is because I really, honestly, don't know where to put this question. If I knew what the problem is about, I'd have looked up on the Internet before asking.

So, I've made a picture explaining my problem : http://i.imgur.com/EkQZq.png .

If anyone can explain me how to solve this kind of problem and tell me what domain it is related to, it would be greatly appreciated.

Thanks already.

Re: Finding a point position on a shape after the shape was rotated

This is a standard problem if you allow some changes.

First lets say the center is ; that is your .

Then if the circle most have radius of say five.

The ‘red’ point has well-known coordinates:

If you let then that rotates the point to the point .

Does that help?

Re: Finding a point position on a shape after the shape was rotated

Hello, Minikloon!

Another solution . . .

Point lies on the circle with center and radius

The coordinates of are: .

Re: Finding a point position on a shape after the shape was rotated

Quote:

Originally Posted by

**Soroban** Hello, Minikloon!

Another solution . . .

Another solution???

Come on, that is identical to the solution that I posted. Is it not?

Please correct me if I am wrong. How is it __another__ solution?

Re: Finding a point position on a shape after the shape was rotated

Hello, Plato!

Don't get your shorts in a knot . . . *identical?*

You made some changes . . . placing the center at the origin.

. . I didn't ... I solved it using the original information.

I believe that even the touchy moderators will agree

. . that I made a significant contribution.