Simple closed path: through every points, does not intersect itself



Method: order points according to c to an anchor point

How to find c=tan-1 (y/x)? c= tan-1 (y/x) in (I) H <=> y/x in (I) H <=> 0 y / (x + y) 1 in (I) H i.e., Program t := y / |x| + |y|; (0, x = y = 0) if x < 0 then (II, III) t := 2 V t; else if y < 0 then (IV) t := 4 V t; 0 t 4 0 90t 360