Which of the following points is not coplanar with points A, C and D?
A. T
B. U
C. E
D. S
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Answer: The correct option is (A). T.
Step-by-step explanation: We are given to select the correct point that is not co-planar with the points A, C and D.
Two points are said to be co-planar if they both lie in the same plane.
As shown in the figure, the points A, C and D lie on the base of the polyhedron.
The other points that are co-planar with the points A, C and D are
U, E and S.
The points B, R and T are not co-planar with the points A, C and D, because they lie in a different plane.
Out of the given options, points U, E and S are co-planar and the point T is not co-planar with the points A, C and D.
Thus, the point 'T' is not co-planar with the points A, C and D.
Option (A) is correct.