Can someone me with this question?

  R(-4g, 0)

Step-by-step explanation:

Since the trapezoid is isosceles, point R is as far to the left of point M as point O is to the left of point H. That distance is g, so we need to add -g to the x-coordinate of M to get the x-coordinate of R. The y-coordinate of R is the same as the y-coordinate of H, 0.

Point R is (-4g, 0).