Constrains the angle between two lines or straight polyline segments; also constrains the angle of an arc or polyline arc. (This command is equivalent to the Angular option of the DIMCONSTRAINT command.)
Accessing the Command
command bar: dcangular
menu bar: Parametric  2D Constraints  Angular
ribbon: Parametric  2D Constraints  Angular
toolbar: 2D Constraints 
: dcangular
Prompts you in the command bar:
Select first line or arc or [3Point] <3Point>: (Select a line or straight polyline segment, or an arc or polyline arc segment, or else press Enter to select the 3Point option)
The angle of the entity is now constrained, although the entity can still be moved, rotated, and so on.
Command Options
Option 
Description 
Select first line 
When you select a line or straight polyline segment, prompts you:

Select arc 
When you select an arc or a polyline arc segment, prompts you

3Point 
Creates an angular constraint between three valid constraint points. Prompts you:
The abbreviation for this option is 3P. 
Procedures
Related Commands
DimConstraint  applies a dimensional constraint to an entity or between constraint points on entities; converts associative dimensions to dynamic dimensions.
GeomConstraint  applies geometric relationships between entities and/or valid constraint points on entities.
DcAligned  constrains the distance between two points.
DcConvert  converts an associative dimension to a dimensional constraint.
DcDiameter  constrains the diameter of a circle or an arc.
DcHorizontal  constrains the horizontal distance (Xdistance) between two points with respect to the current coordinate system.
DcLinear  constrains the horizontal distance (Xdistance) or vertical distance (Ydistance) between two points with respect to the current coordinate system.
DcRadius  constrains the radius of a circle or an arc.
DcVertical  constrains the vertical distance (Ydistance) between two points with respect to the current coordinate system.
ConstraintBar  controls the display of the constraint bar of entities.
DcDisplay  allows to set dimensional constraints to be displayed or hidden.
DelConstraint  removes all dimensional and geometrical constraints from an entity.
CleanUnusedVariables  purges variables not used in constraint expressions and not linked to dimensions.
Parameters  manages 2D dimensional constraint parameters and user variables in the current drawing.