An example for the appearance of shapes through additional forms that are not actually closed, but support the impression of a closed form in between them.
function setup() {
var canvas = createCanvas(500, 500);
canvas.parent('sketch');
var a = 0;
var b = 200;
noStroke();
fill(60);
ellipse(b, b, b + 150, b + 150);
strokeWeight(30);
stroke(255);
line(a, b - 100, b * 2, b);
line(a, b, b * 2, b - 30);
line(a, b + 70, b * 2, b + 110);
line(a, b - 140, b * 2, b / 4);
strokeWeight(2);
line(b - 20, b * 2, b + 100, a);
line(b - 5, b * 2, b + 70, a);
line(b - 10, b * 2, b + 80, a);
line(b - 25, b * 2, b + 10, a);
line(b - 70, b * 2, b - 170, a);
line(b - 140, b + 130, b - 40, a);
}