Overview of Dimensions

Dimensions calculate linear, angular, and coordinate measurements of geometry, and then represent those calculations as entities in the current drawing. Dimensions show measurements of existing geometry, usually by attaching to the existing geometry whose parameters they measure. Dimension entities can calculate length measurements, angle measurements, radius and diameter measurements, and coordinate locations.

Dimension entities can be one of the following types:

Aligned linear dimension — Calculates the distance between two points.
Rotated linear dimension — Calculates the distance of the inclined projection between two points.
Arc-length dimension — Calculates the length of a circular arc.
Two-line angular dimension — Calculates the angle between two lines or the opening angle of a circular arc.
Three-point angular dimension — Calculates an angle using three points.
Diametric dimension — Calculates the diameter of a circle or circular arc.
Radial dimension — Calculates the radius of a circle, circular arc, or polyline arc segment.
Radial large dimension — Calculates the radius of a large circle, circular arc, or polyline arc segment using a jogged dimension.
Ordinate dimension — Calculates the x- or y-coordinate of a point.

Dimension entities can consist of different visual elements:

Dimension line — A line that is a graphical representation of the dimension direction and value. A dimension line is parallel to the feature that is being dimensioned and extends to extension lines.
Extension line — A line that encloses a dimension line. An extension line extends from the feature that is being dimensioned to the dimension line.
Dimension text — Text that usually contains the calculated measurement and can also include prefixes, suffixes, and tolerances.
Arrowhead — A symbol that marks the ends of the dimension line.
Leader — A line from the text annotation to the referenced object.
Center mark — A cross marker that indicates the center of arc or circle objects.
Centerline — Broken lines crossed in the center of arc or circle objects.

See Also