# Center of a 3D (xyz) circle

January 20, 2010

Posted By Brad Ott on 1/19/2010 at 4:09 PM

Okay flame on, I can take it, maybe a dumb question, but do you ever have one of those days...?

At any rate (please correct me if I am wrong, but...) I think most of our cogo software when we supply it with 3 points on a circle & it gives us coordinates on the center (radius point) it is doing so on the horizontal plane?

I have 3 (xyz) sets of coordinates (actually 6, because I did this twice in different places on the same circle) on a circle that is significantly tilted say 30 or 40 degrees away from anything close to a horizontal plane.

My question is this, how do I get the center xyz coordinate of this circle? Does anyone have a spreadsheet or some old high school formula that I have long forgotten? I am thinking that first I need to somehow identify the plane through the 3 points first, and then....?

Many thanks, Brad

To read the rest of this thread go to www.i-boards.com/bnp/pob/messages.asp?MsgID=1521184&ThreadID=143462&IsResponse=False#1521184.

Okay flame on, I can take it, maybe a dumb question, but do you ever have one of those days...?

At any rate (please correct me if I am wrong, but...) I think most of our cogo software when we supply it with 3 points on a circle & it gives us coordinates on the center (radius point) it is doing so on the horizontal plane?

I have 3 (xyz) sets of coordinates (actually 6, because I did this twice in different places on the same circle) on a circle that is significantly tilted say 30 or 40 degrees away from anything close to a horizontal plane.

My question is this, how do I get the center xyz coordinate of this circle? Does anyone have a spreadsheet or some old high school formula that I have long forgotten? I am thinking that first I need to somehow identify the plane through the 3 points first, and then....?

Many thanks, Brad

To read the rest of this thread go to www.i-boards.com/bnp/pob/messages.asp?MsgID=1521184&ThreadID=143462&IsResponse=False#1521184.