How do you calculate the cross section area of a rectangular channel in square feet?

To find the cross-sectional area of a rectangular channel in square feet, you multiply the average width by the average depth. This calculation is essential because the cross-sectional area directly influences the flow rate and the overall hydrodynamics of the water body being studied or managed.

When measuring a rectangular channel, the width represents the horizontal distance across the channel, and the depth measures how deep the water is at its deepest point. The resulting product gives the area in square feet, which can be utilized in various aquatic pest control management strategies or environmental assessments.

The other choices either provide incorrect methods for calculating the area or do not reflect the proper relationship between width and depth necessary for area determination. For instance, simply adding or subtracting the width and depth does not yield a relevant area measurement, and dividing these dimensions would give an inappropriate dimensional unit. Thus, the correct approach is to multiply these two measurements.