If the points $A(0, 1, 2)$,$B(2, -1, 3)$,and $C(1, -3, 1)$ are the vertices of a triangle,then the triangle is

If the points $(2,4,-1), (3,6,-1)$ and $(4,5,1)$ are three consecutive vertices of a parallelogram,then its fourth vertex is

$A(3, 2, -1), B(4, 1, 1), C(6, 2, 5)$ are three points. If $D, E, F$ are three points which divide $BC, CA, AB$ respectively in the same ratio $2: 1$,then the centroid of $\triangle DEF$ is

The centroid of a tetrahedron with vertices at $A(-1, 2, 3)$,$B(3, -2, 1)$,$C(2, 1, 3)$,and $D(-1, -2, 4)$ is:

Let $A (2, 3, 5)$,$B (-1, 3, 2)$ and $C (\lambda, 5, \mu)$ be the vertices of a $\Delta ABC$. If the median through $A$ is equally inclined to the coordinate axes,then

If the origin is the centroid of the triangle for which $(-2, 3, 4)$ and $(3, -1, 5)$ are two vertices,then the third vertex is