let's go back to the reference. what does it say about rect()? it also looks like it has 4 values here,  inside the parentheses, 4 parameters. and it says: 'draws a rectangle to the screen. a rectangle is a four-sided shape with every angle at ninety degrees. the first two parameters set the location, the third sets the width, and the fourth sets the height.' so this is identical to the ellipse. ok, then let's copy, I'm just gonna hit CTRL-C to copy this line, and CTRL-V to paste it. and here I type rect instead of ellipse. so now we will have 2 shapes drawn on the screen. and I run the program, and: hm ... that's interesting! why is the rectangle not centered with the circle? you can see that the top left corner is on the center but if would be nicer maybe  if they are both centered on the same location? does it say something here about this? 'the origin is changed with the rectMode() function.' hm, this origin sounds like what we're looking for. 