createCanvas(800, 600);

}

​

function draw() {

  background(230, 230, 250);

​

  // calculates rectangle size based on canvas dimensions

  let rectWidth = width / 2;

  let rectHeight = height / 2;

​

  // draw the rectangle in the center

  rect((width - rectWidth) / 2, (height - rectHeight) / 2, rectWidth, rectHeight);

}

​