You can create five basic types of dimensions: linear, angular, radial, diametral, and ordinate.
You can create dimensions for existing entities by selecting them, or you can create dimensions by selecting points within a drawing. For example, you can create a linear dimension either by selecting the entity to be dimensioned or by specifying the first and second extension line origins.
Dimensions indicate the measurement values of objects (e.g. length or width), distance or angles among objects, or the distance between feature point and the specified origin. You can create dimensions that can be horizontal, vertical, aligned, rotated, coordinate, baseline, or continued.
When you create a dimension, the program draws it on the current layer, using the current dimension style. Each dimension has an associated dimension style, which controls the appearance of the dimension, such as the types of arrowheads, text style, and colors of various components. You can modify existing dimension styles by changing any of the dimension variable settings, and the new dimension style is visible soon after you confirm the modification.
You can use the QDIM command to create or edit a series of nonassociative dimensions.
Parts of a Dimension
Dimensions have several distinct elements: dimension text, dimension lines, arrowheads, and extension lines.
Dimensions can also contain other optional components. A leader is a line leading from a feature of the drawing to an annotation. Leaders begin with an arrowhead, and you can use them to place a dimension away from the dimension line or to add notes. When you create a radial dimension, you can add a center mark, which is a small cross that marks the center of a circle or an arc, or you can add centerlines, which are crossing lines that extend out from the center of a circle or an arc.
Dimension text: a character string that usually indicates the measurement value, includes prefixes, suffixes, and tolerances .etc.
Dimension line: indicates the direction and extent of a dimension. For linear dimensions, it displays as a line, for angular dimensions, it displays as an arc segment.
Arrowhead: usually displayed at both end of the dimension line. You can specify various sizes and shapes for arrowheads or tick marks.
Extension line: extends from the object to the dimension line, in order to define dimension ranges.
Center mark: a small crossing tag that marks the center of a circle or arc.
Centerline: a crossing dashed line that marks the center of a circle or arc.
DIMANGULAR: Creates an angular dimension
DIMDIAMETER: Creates diameter dimensions for circles and arcs
DIMEDIT: Edits dimensions
DIMLINEAR: Creates linear dimensions
DIMORDINATE: Creates ordinate point dimensions
DIMRADIUS: Creates radial dimensions for circles and arcs
DIMSTYLE: Creates and modifies dimension styles
PROPERTIES: Controls properties of existing objects
QDIM: Quickly creates a dimension
EXPLODE: Breaks a compound object into its component objects
LIST: Displays database information for selected objects
OPTIONS: Customizes the ZWCAD settings
System Variables Reference