If the final calculated area refers to the area on the drawing, then:

The area calculated with the scale of 1: 200 multiplied by (16/9) is the area calculated with the scale of 1: 150; Multiplied by 4, it is the area calculated with the scale of 1: 100.

(Area ratio has nothing to do with shape, but only with proportion.)

Examples are as follows:

It is actually a square of 6 meters by 6 meters.

With the ratio of 1: 200, it becomes a 3 cm× 3 cm square with an area of 9 square centimeters;

With the scale of 1: 150, it becomes a square with an area of 16 square centimeter;

With the ratio of 1: 100, it becomes a 6 cm× 6 cm square with an area of 36 square centimeters.