OL_HeringIllusion

r=300
n=40;
function setup() {
  createCanvas(400, 400);//create  the canvas
  stroke(0,0,100)
}
function draw() {
  translate(200,200)
  for(let i=0;i<n;i++){ 
   if(i>2&&i<n-2) line(r*sin(PI/n*i),r*cos(PI/n*i),r*sin(PI/n*i+PI),r*cos(PI/n*i+PI));//Activity: Try to rewrite this code using slope instead of a rotation
  }
  strokeWeight(2)
  stroke(200,0,0)
  line(-50,-400,-50,400)
  line(50,-400,50,400)
  noLoop();
}