function setup() {

  createCanvas(400, 400); //create the canvas

  background(255); //black background

  frameRate (3); //frame rate or speed

}

​

function draw() {

  stroke(random(255), random(255), random(255)) //random linecolor

  strokeWeight(random(50));//random line width

  x1 = random(400);//random x1 value

  y1 = random(400);//random y1 value

  x3 = random(400);

  y3 = random(400);

  line1 = line(x1,y1,x2,y2) //draw line from center (200,200) to random (x1,y1)

  m1 = (y2-y1)/(x2-x1); //calculate slope of line1

  m2 = -1/(m1) //perpendicular slope is -1/m for line 1

  b2 = y3-x3*m2 //find b of line2 (y = mx+b) using a new point (x3,y3)

  line(x3,m2*x3+b2,x1,m2*(x1)+b2) //two points (x2,y2) and (x1,m2(x1)+b2)

}