You can apply equal curve length relations between any two entities such as a line, spline, arc, or circle, depending on the type of entity.
You can still use the equal 
relation to make the lengths of line segments equal. You can use the equal curve length 
relation for
adding relations between a circle and an arc, two circles, or two arcs. You can
also use the equal curve length relation for adding relations between a line and a circle, a
circle and a spline, and a spline and a line.
When you use these relations:
- You can create relationship pairs for each set of relations that adhere to all existing logic for creation, display, and deletion.
- Two or more homogenous entities can have the relations applied to them at the same time.
- You can apply the equal curve length relation to a projected curve and another entity, except for another projected curve.
- The equal curve length relation is applicable within a 2D or 3D sketch.
- Relations are hidden in the graphics area when you clear
.
- You can create a fixed spline when you select a spline and any other sketch entity.
You can access these relations from the Sketch Relations context toolbar, the Add Relations PropertyManager.