Answer:
The points A, S and R are colinear.
Explanation:
Notice that the figure in question is a pyramid, where the points A, C, B and R are all vertices. Now, the point S is not a vertex of the pyramid, instead it is on an edge, specifically on the edge determined by the vertices A and R. With this, we can affirm that the point S is on the segment defined by the points A and R.
Now, from the axioms of geometry we know that two points are always in a line. But when we have three, the same assertion is not true, just recall the triangles. So, when three (or more points) are on the same line (or segment) we say that they are colinear.
Thus, the points A, S and R are colinear.