What is the total length of a rectangular weir if it is 10 ft?

In the context of the question about the total length of a rectangular weir, it is important to understand what is being asked. The problem states that the total length is given as 10 ft, and the question is simply seeking to confirm this measurement.

A rectangular weir is typically characterized by its length, which is the horizontal distance across the top. If the question specifies that the total length of the weir is 10 ft, then this is the correct and definitive answer. This understanding is fundamental in civil engineering, particularly in hydrology, where weirs are commonly used to measure flow rates in open channels.

The other choices presented do not reflect the measurement stated in the question and cannot represent the total length of the weir when it is specifically given as 10 ft. Therefore, recognizing the provided information is key to arriving at the correct conclusion.