The command Midpoint(p1, p2) computes the midpoint of the line segment joining p1 and p2.

p1 and p2 must specify points of the same dimensionality (and orientation, when each of the points is a Vector).

This command is part of the Student[Precalculus] package, so it can be used in the form Midpoint(..) only after executing the command with(Student[Precalculus]).  However, it can always be used in the form Student[Precalculus][Midpoint](..).