Is a regular tetrahedron of side unity.

MATHEMATICS · Single correct · CBSE · Mathematics · Three-Dimensional Geometry · Three-Dimensional Geometry

Problem

OABC

is a regular tetrahedron of side unity. (1) the length of perpendicular from one vertex to opposite face is

\sqrt{2}/3

(2) the perpendicular distance from mid-point of

\overline{OA}

to the plane

ABC

1/\sqrt{6}

(3) the angle between two skew edges is

\pi/2

(4) the distance of centroid of the tetrahedron from any vertex is

\sqrt{3}/8