Answer:
Point U is the point that satisfies the definition of betweenness.
Step-by-step explanation:
We are given that the three points S,U and N are collinear (i.e. they lie on a line).
By definition of betweenness we mean, a point B is between two other points A and C if all three points are collinear and AB +BC = AC.
Hence, from the given property:
NU + US = NS we have:
U is the mid point of the line joining the points N and S.
Hence, the point that satisfies the definition of betweenness is:
Point U.
