# Find centre of rotation from two locations

Ultimately I need to get c from the image and have a, b and that it takes 90 degrees to get a to d.

My solution to this was to rotate a around to get to d by the rotation. Then use the Y value from a and X from d to get c.

So far I an having trouble getting the rotation of a to d to work properly, what am I doing wrong in the rotation?

    Vector3 d = (Quaternion.Euler(0f, 0f, rotation) * (a - b)) + b;

• You're code and description seem to match up, but the image definitely does not show d as being rotated from a 90 degrees around b. – Jay Jan 6 '18 at 9:17
• @Jay Looking back on it again I get what you mean, I guess what I'm trying to say is that I'm attempting to get to d so that I can work out c. How I get d or c is that part that i'm stuck on. I'm sure that all the information that i need is there... I just need to piece it together... – user3797758 Jan 7 '18 at 18:00