// coordin.h -- structure templates and function prototypes
// structure templates
struct Polar
{
    double distance;    // distance from origin
    double angle;        // direction from origin
};
struct rect
{
    double x;        // horizontal distance from origin
    double y;        // vertical distance from origin
};

// prototypes
Polar rect_to_polar(rect xypos);
void show_polar(Polar dapos);

