If you need to constrain an Arc based on a known arc length you have two ways:


Constrain arc length based on Chord Length (calculated) and Radius (known value)


Constrain arc length based on Angle (calculated) and Radius (known value)


Formula to calculate Angle=(180/PI)*ArcLength/radius


Formula to calculate Chord=2*radius*sin(angle/2)

The linked file below uses a known Arc Length as an example and has been created in TopSolid'Wood 2017 v6.18