What is the purpose of construction lines in technical drawings?

Construction lines serve a crucial role in technical drawings by establishing proportions and layout. They are often drawn lightly and are not intended to be part of the final presentation. Instead, they help designers and drafters create a framework on which they can accurately build their drawings. By outlining major dimensions and key elements, construction lines ensure that all parts of the design are properly proportioned and aligned before the final details are added. This strategy aids in achieving consistency and accuracy within the overall design, making it easier to visualize and communicate the intended structure or object.

While other options present tasks associated with specific line types—like showing hidden edges, creating rough outlines, or denoting center points—these functions are not the primary purpose of construction lines. Instead, construction lines focus on guiding the overall geometry and layout of the drawing.