What is the paper size of Architectural D?

The paper size for Architectural D is indeed 36 inches by 24 inches. This size is commonly used in architectural drawings for plans, sections, and details because it provides ample space for detailed graphics and annotations. The dimensions are particularly suited for large-scale constructions and can accommodate a variety of drawing types, making it a standard choice in the architecture industry.

The other options reflect different paper sizes that do not align with Architectural D specifications. For instance, 12 x 9 and 18 x 12 are significantly smaller and more suitable for smaller projects or sketches rather than formal architectural presentations. The 24 x 18 size, while larger than the smaller options, still does not reach the dimensions of Architectural D, which is specifically designed for more comprehensive drawings. Thus, the correct answer evaluates the standard practices in architectural documentation and ensures that adequate space is available for a detailed representation of designs.