i want to create a triangle from 2 3d vectors

Hi i am trying to do a triangle from 2 given 3d vectors and i want the triangle to be symetrical and i dont know how to get the last 3d vector

and with symetrical i mean the sides are equal length

There is no last vector, what you’re looking for is a circle. Then you can define where in that circle you want to put your last point.

        Vector3 dir = (B-A).normalized;
        float dist = Vector3.Distance(A, B);
        Vector3 perp = Vector3.Cross(dir, Vector3.up).normalized;
        C = Quaternion.AngleAxis(60, perp) * dir * dist;