conversion to create elliptical arc

archimedes data format:

Point 1 center
Point 2 more to end the right of center
Point 3 higher end starting center
4 beginning point of the arc
5 end point of the arc
the arc is always created counterclockwise

arco.arc file data to test
1 point x = 5 y = 0
point 2 x = 0 y = 15
Item 3 x = 5 y = 5
Item 4 x = 5 y = 5
Item 5 x = 0 y = 15
