A drawing that shows the interior of an object or structure as seen on a cut surface; a cross-sectional view or drawing.
この建物の断面図を見れば、配管の位置がよくわかります。
If you look at the building's cross-section, you can clearly see the locations of the pipes.
設計図には平面図と断面図の両方を必ず添付してください。
Be sure to attach both the floor plans and cross-sectional drawings to the design documents.
模型と断面図を比べると、内部構造が理解しやすい。
Comparing the model with the cross-section makes the internal structure easier to understand.