​

function setup() {

  createCanvas(400, 400);

  angleMode(DEGREES);

}

​

function draw() {

  background(0);

  translate (200,200); //translate moves the position of the objects.

  stroke (255);

  line (0,0,50,50);

  rotate(angle); //because i added "rotate" after the line, only the rectangle rotates, while the line doesn't move.

  fill(255);

  rect(0,0,100,50);

  angle=angle+1 //this function makes the rectangle rotate.

}