What does a dimension line typically include?

A dimension line typically includes a line with small arrows at each end. This format indicates the extent of a measurement and clarifies where the dimensions start and end. The arrows serve to point precisely to the points being measured on the drawing, making it clear to the viewer what specific distance is being referred to.

In architectural and engineering drawings, dimension lines are an essential part of conveying the size and scale of elements within a project. They are distinct from other types of lines used in a drawing, such as object lines or construction lines, due to their specific function and style. The inclusion of the arrows at both ends helps to visually separate the dimension from other lines and further confirm that the viewer should look to the indicated values for the actual measurements.

The other choices do not correctly represent the standard format of a dimension line, which is why they are not correct. Dimension lines primarily focus on clarity and precision in indicating measurements, which is achieved through the use of arrows rather than letters, dashed lines, or solid lines without arrows.