{Try it.  Then try replacing drawpoly() with drawpolyfilled().
 How many sides does the polygon have, compared to the number
 of points in the polygon array?
 }

program polygons(input,output);

import graphics;

const	windowWidth = 600;
		windowHeight = 600;
		bottom = 100;
		left = 100;
       

var		 polygon : polyarray;

procedure StartGraphics;
begin
  { open a window }
 	initializegraphics;
	createwindow(bottom,left,bottom+windowHeight,left+windowWidth);
	
  { flood the window with a black background }
	setrgbcolor(0,0,0);
	flood; 
	flushgraphics
end;

begin
	StartGraphics;

	polygon[1].x := 200;
	polygon[1].y := 100;
	polygon[2].x := 400;
	polygon[2].y := 100;
	polygon[3].x := 500;
	polygon[3].y := 200;
	polygon[4].x := 400;
	polygon[4].y := 300;
	polygon[5].x := 200;
	polygon[5].y := 200;
	
	setrgbcolor( 0, 1, 0 );
	drawpoly( 5, polygon );
	flushgraphics;
	
	readln
end.