A staircase has a rise of 1.73 m over a run of 2.09 m. What is the slope of this staircase?

A 0.83

B 1.31

C 3.82

D 1.21

The slope of a staircase is defined as the rise (vertical change) divided by the run (horizontal change).

In this case, the rise is 1.73 m and the run is 2.09 m.

Therefore, the slope of this staircase is 1.73/2.09 = 0.83.

Therefore, the correct answer is A) 0.83.