What is shown on a sectional drawing?

A sectional drawing is specifically designed to provide a cutaway view of a building, showcasing the internal structure and layout. This type of drawing allows for a better understanding of the dimensions, materials, and relationships between different components of the building, such as walls, floors, and ceilings. By illustrating various levels and sections, a sectional drawing helps identify how different areas of a structure interact and how services, such as electrical or plumbing systems, can be integrated within the overall design.

The other choices, while valid types of drawings, serve different purposes. A bird's eye view of a structure is more of an aerial perspective, focusing on the exterior layout without detailing the internal components. A topographical layout is used to depict the contours and elevations of land, which is essential for landscaping or site analysis but does not reveal the internal construction of a building. Lastly, a site plan provides an overview of the property and positions buildings within it, including landscaping and infrastructure, but does not delve into the internal structure of the buildings themselves. Thus, the cutaway view in a sectional drawing is crucial for understanding building design and function at a detailed level.