With D1 at (9, 0) and R1 at (11.5, 0), the width is 2.5 units (50 cm if 1 unit = 20 cm). This is quite narrow and would not easily accommodate a wheelchair.

The coordinates of point D1 are (9, 0). This means the point is located 9 units to the right of the origin along the x-axis and has no vertical displacement from it.

The door’s distance from the left wall is its x-coordinate, which is 9 units. Its distance from the x-axis is its y-coordinate, which is 0 units as it lies on the horizontal axis.