In a circle, you can :
- compute the ray if you know cord and arrow
- compute the cord if you know ray and arrow
- compute the arrow if you know cord and ray just input the two datas you know and clic the button in front of the unknown value.
This project uses Circle.dll (You can find the project in my repositories, in order to compile the dll) with a static way. Remark : in the circle project, you will find also the circleUnit.pas used in this project.