draw an arrow method for Processing

drawArrow.pde

void setup() {
  size(400, 400);
  stroke(255);
  noLoop();
}

void draw() {
  background(255);
  stroke(255, 0, 0);
  fill(255, 0, 0);
  for (int i = 0; i < 100; i++) {
    drawArrow(width / 2, height / 2, (float)random(width), (float)random(height));
  }
}

void drawArrow(float x1, float y1, float x2, float y2) {
  float a = dist(x1, y1, x2, y2) / 50;
  pushMatrix();
  translate(x2, y2);
  rotate(atan2(y2 - y1, x2 - x1));
  triangle(- a * 2 , - a, 0, 0, - a * 2, a);
  popMatrix();
  line(x1, y1, x2, y2);  
}

This will be really helpful! Thank you!