Question

pipe less than 12\ is measured by the:

inside diameter

schedule

outside diameter

Explanation:

In pipe measurement, pipes with a diameter less than 12 inches are typically measured by their inside diameter. Schedule refers to the wall thickness, and outside diameter is used for larger pipes or specific pipe types (like steel pipes in some cases), but for pipes <12", inside diameter is the standard measurement for sizing (e.g., in plumbing and many pipe applications).

Answer:

A. inside diameter