​

//weight and height of canvas, change here!

let width=800;

let height=400;

​

//middle point of the rectangle

let leftX=width/4;

let topY=height/4;

let rightX=3*width/4;

let bottomY=3*height/4;

​

​

function setup() {

  createCanvas(width, height);

}

​

function draw() {

  background(20);

  stroke(255);

  strokeWeight(5);

  //can recognize easily

  line(leftX,topY,rightX,topY);

  line(rightX,topY,rightX,bottomY);

  line(leftX,bottomY,rightX,bottomY);

  line(leftX,topY,leftX,bottomY);

}