Which of the following sets of points are non-collinear?

If $D(2, 1, 0)$,$E(2, 0, 0)$,and $F(0, 1, 0)$ are mid-points of the sides $BC$,$CA$,and $AB$ of $\triangle ABC$,respectively,then the centroid of $\triangle ABC$ is

If $G(2, -1, 2)$ is the centroid of tetrahedron $OABC$ where $O=(0, 0, 0)$ and $G_1$ is the centroid of $\triangle ABC$,then $\left|\overline{O G_1}\right|=$

If the coordinates of the points $A, B, C$ are $(-1, 3, 2)$,$(2, 3, 5)$,and $(3, 5, -2)$ respectively,then $\angle A = \dots^o$.

If the midpoints of the sides $AB$, $BC$, and $CA$ of a triangle are respectively $D(1, 2, -3)$, $E(3, 0, 1)$, and $F(-1, 1, -4)$, then the centroid of the triangle $ADF$ is

$\triangle ABC$ has vertices at $A \equiv (2, 3, 5)$,$B \equiv (-1, 3, 2)$ and $C \equiv (\lambda, 5, \mu)$. If the median through $A$ is equally inclined to the axes,then the values of $\lambda$ and $\mu$ respectively are