size(400,400); //Sets the size of 400 by 400 pixels
noStroke(); //Invisible line around the figure
fill(255,0,0); //Fill the figure with red color
rect(0,0,200,200); //Square 200 by 200
fill(0,255,0); //Fill the figure with green color
rect(200,0,400,200); //Square 200 by 200
fill(0,0,255); //Fill the figure with blue color
rect(0,200,200,400); //Square 200 by 200
fill(125); //Fill the figure with gray color
rect(200,200,400,400); //Square 200 by 200
strokeWeight(4); //thickness of the line around the circle
stroke(0); //Black line around the circle
fill(255,255,255,200); //Transparent white color
ellipse(200,200,100,100); //Circle 100 by 100
Part #3
http://www.openprocessing.org/sketch/87903
