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                var  x2 = 200, y2 = 200; // initial ordered pairs (at center of screen)
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)