Let me really blow your mind with the few tools now at our disposal.
Give spirals() a whirl!

function spirals(angle=75) {
  cs(); home();
  spiral(angle); angle++;
  if (angle<145setTimeout(spirals,500,angle);
}
Back to Basics

The first task that is usually given to Turtle Graphics beginners is draw a square of side 100. Have a go before clicking here to reveal my work.

function square(d=100) {
  for (var i=0; i<4; i++) { fd(d); rt(90);}
}
function test() {
  square();
}

Not quite so easy is draw a triangle with each side 100. Have a go before clicking here to reveal my work.

function triangle(d=100) {
  for (var i=0; i<3; i++) { fd(d); rt(120);}
}
function test() {
  triangle();
}