Final answer:
The lines commonly used on a blueprint are sometimes called the line types of lines. These line types include outline lines, implied lines, and leading lines.
Step-by-step explanation:
The lines commonly used on a blueprint are sometimes called the line types of lines. These line types include outline lines, which define the path around the edge of a shape, and implied lines, which can be mentally connected to create lines in our minds.
Additionally, leading lines are also used in photography to guide the viewer's eye through the composition.