How should a fall be calculated when given a slope ratio?

To calculate a fall based on a slope ratio, you take the total rise and divide it by the slope factor. The slope ratio is typically expressed in the form of "rise over run," indicating how much vertical rise occurs over a certain horizontal distance. The slope factor is derived from this ratio and effectively indicates how steep the slope is. Dividing the total rise by this factor provides the correct calculation for determining the fall.

Considering the other approaches, multiplying the total rise by the slope ratio does not yield a meaningful or correct representation of fall; it would imply a direct increase rather than a reduction associated with calculating the fall. Applying the slope ratio directly to the length lacks consideration for the actual rise, which is essential in performing the calculation accurately. Lastly, averaging the rise and run does not apply to slope ratio calculations as it fails to accurately represent the relationship between vertical and horizontal distances.

Thus, the method of dividing total rise by the slope factor accurately reflects the mathematical relationship inherent in slope, leading to the determination of the fall necessary for construction calculations.