Sketcher ConstrainEqual

From FreeCAD Documentation

Sketcher ConstrainEqual

Menu location
Sketch → Sketcher constraints → Constrain equal
Default shortcut
Introduced in version
See also
Sketcher Constrain radius


The Constrain Equal constraint forces two or more line segments in a line, poly-line or rectangle to have equal length. If applied to arcs or circles the radii are constrained to be equal. It cannot be applied to geometry primitives which are not of the same type (e.g. line segments and arcs).


The example sketch below contains a number of sketch primitives (line, poly-line, rectangle, arc and circle).

Select two or more line segments (e.g. line and one side of the rectangle).

Click on Constrain equal in the Sketcher toolbar (in either the Sketcher or Part Design workbenches) or select the Constrain Equal menu item from the Sketcher constraints sub menu item in either the Sketch or Part Design menu item depending upon which workbench is selected (Sketcher or Part Design) to apply the constraint to the selected items.

Now select the arc and the circle in the sketch.

and apply Constrain equal as before.

Now select the line segment, all segments of the poly-line and one of the remaining unconstrained sides of the rectangle

and apply Constrain equal as before.

Select the line segment and the arc

and apply Constrain equal as before. A pop-up message indicates that the constrained items have to be of the same geometrical type (lines of zero curvature or lines of non-zero curvature).


Sketch.addConstraint(Sketcher.Constraint('Equal', Edge1, Edge2))

The Sketcher scripting page explains the values which can be used for Edge1 and Edge2 and contains further examples on how to create constraints from Python scripts.