Sunday, March 30, 2014

The Random Chord Probability Problem

   I am still playing with geometric probability. This Scratch project looks at an experimental (Monte Carlo) method for determining the probability that the chord of a circle, picked at random, is longer than the radius of the circle.    
   The real purpose of this project is to set the stage for using three additional Scratch programs to explore the Joseph Bertrand Paradox. His paradox indicates that how you select the random chord in a similar circle problem is important and in fact, leads to three different answers!
   This video shows the result of running the experiment.

   Repeated runs of the program indicate that the theoretical probability is two-thirds.
   The Scratch project can be viewed and downloaded by clicking on the following link.

  Detailed descriptions (PDF format) of the code and theoretical solution to the problem can be had by sending an email request to


  1. I found your blog on Google and read a few of your other posts. I just added you to my Google News Reader. You can also visit Scratch Programming For Kids for more Techno Smart Kids related information and knowledge, Keep up the great work Look forward to reading more from you in the future.

    1. Thank you for your interest in my blog. I am not very active on Scratch at the moment but I do respond to comments and questions I receive regarding specific blog posts. I have had many requests for the Projectile Motion pdf as I derive the working equation as a quadratic equation. I wish technosmartkids great success. You are doing what the public schools have failed to do since I bought my first computer, an 8K Commodore PET.