Which of these structures is considered a type in the ExAC exam?

Steel frames are considered a type in the ExAC exam because they represent a fundamental construction method that is widely used in architecture and engineering. Steel frames are integral to creating large, open spaces and provide a strong structural support system for buildings, which is essential knowledge for architects. Understanding the properties of steel, including its strength, durability, and flexibility, is crucial in architectural design and construction practices.

On the other hand, while plastic structures, glass houses, and fiberglass huts may have specific applications in architecture, they are not as foundational or widespread in the same way that steel frames are within the context of standard building practices examined in the ExAC. Steel framing is a critical component of many architectural strategies and is important for maintaining structural integrity, thus making it a key topic of focus in the examination.