/*
  next version much better. It still works out all
  the co-ordinates, but this function can draw
  a triangle of any size at any position
*/

void draw_triangle(const double x1,
                   const double y1,
                   const double side)
{ move_to(x1, y1);
  const double x2 = x1 + side/2,
               y2 = y1 + side/2*tan(60.0 * pi / 180.0);
  draw_to(x2, y2);
  const double x3 = x1 - side/2,
               y3 = y2;
  draw_to(x3, y3);
  draw_to(x1, y1); }


void main()
{ make_window(500,500);
  set_pen_color(color::red);
  set_pen_width(3);

  draw_triangle(250, 50, 300);
  draw_triangle(250, 100, 150); }