UnitCircle

function setup(){
  createCanvas(windowWidth,windowHeight);
  angleMode(DEGREES);
  noFill()
  r=min(width,height)/3
}

function draw(){
  background(255,255,255)
  a=frameCount/4
  translate(width/2,height/2);
  text("(cos(θ), sin(θ), tan(θ))",-width/2+20,-height/2+20)
  axes()
  circle(0,0,2*r)
  mLine(a)
}

function axes(){
  stroke(0)
  strokeWeight(2)
  line(0,-height,0,height);
  line(-width,0,width,0);
  line()
  strokeWeight(0.1)
  for(let i = 0;i<72;i++){
    push()
    rotate(i*5)
    line(-width,0,width,0);
    pop()
  }
  strokeWeight(2)
}

function mLine(a){
  strokeWeight(3)
  stroke(20,100,200);
  line(0,0,r*cos(a),-r*sin(a))
  line(r*cos(a),-r*sin(a),0,-r*sin(a))
  line(r*cos(a),-r*sin(a),r*cos(a),0)
    tmp="("+str(round(cos(a),2))+", "+ str(round(sin(a),2)) + ", "+ str(round(sin(a),2))+")"
    stroke(0)
    strokeWeight(1)
    fill(0)
    textSize(12)
    translate((r+40)*cos(a)-30,(r+40)*sin(-a))
    text(tmp,0,0);
    noFill()
  
}