function setup() {

  createCanvas(400, 400);

  background('lightgray');

​

  d = random(75, 125);

  stroke(0);

  strokeWeight(3);

  fill(255);

  strokeCap(ROUND);

  //triangle(x1, y1, x2, y2, x3, y3)

  triangle(d, 3*d, width-d, height-3*d, d, d);

}

​

function draw() {

}