Final answer:
Standard steel pipes with diameters of 1-1/4 inch require hangers to be placed a certain distance apart. The distance is determined based on engineering principles, weight of the pipe, material, and load it will be carrying.
Step-by-step explanation:
Standard steel pipes with diameters of 1-1/4 inch require hangers to be placed a certain distance apart. This distance can be calculated using engineering principles and factors such as the weight of the pipe, the material it is made of, and the load it will be carrying. To determine the specific distance, it is important to consult engineering standards and guidelines for pipe support systems.