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Online Education News

Watch this Ted Talk called What We're Learning From Online Education

What's MOOC? Read the New York Times article, Instruction for Masses Knocks Down Campus Walls. Find out which Northwestern faculty members are involved in Udemy's Faculty Project here.

Check out courses that Northwestern plans to offer online through Coursera.

Web-CAT hosts a set of automated testing and grading software and related resource to support computer science learning.

Tech Tips

Need a transparent image or animated gif? Check out this Tekzilla video.

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Hone your math or computer science skills online

I help students age 10 to adult to develop their math and computer science skills. There are two different ways you can learn from me:

1. Take a Course with me at Northwestern (grades 6-12)

I teach a number of courses for the Center for Talent Development on the campus of Northwestern University and online. Some of these courses offer high school credit. The courses I teach are shown below. See the CTD website for a complete list of courses and requirements.

2. Learn on Your Own For Free

I make my videos and resources available on this site for your learning pleasure. Poke around the course pages. There are video and interactive lessons, and lots of links to resources for learning. If you're interested in any of the course material, don't be intimidated by standardized test scores that appear in course requirements. These courses are designed for anybody who wants to invest time and effort in learning something new. Some of the courses require textbooks or software that cost money. My long term plan is to use only free resources for all of my courses.

Contact TJ Leone at or call 847-951-0127.

Many Polygons Project

ManyPolygons is a Java program that uses the ACM/Stanford turtle library to draw a grid of spiraling polygons.

This program was developed for instructional use in a course on Java programming and computer graphics. It employs turtle geometry and trigonometry to explore the geometry of regular polygons. In addition to employing formulas for the radius, the side length, and the apothem, it includes code for finding the aspect ratio of this polygon's bounding rectangle. This aspect ratio is used to organize polygons in a grid pattern and resize the drawing area. The program also uses trig to calculate angles and line lengths for drawing a spiral of polygons. Menus allow users to change the number of rows and columns in a grid of polygons, the number of sides in the polygons, and the number of polygons in a concentric spiral of polygons. A slider allows users to change the starting point of concentric polygons in each spiral.

This work is based on a simpler, non-interactive program, a "chessboard of squares" that contains spiraling squares in a square grid. The "chessboard of squares" problem is proposed as an exercise in Chapter 1 of "Computer Graphics for Java Programmers" by Lee Ammeraal and Kang Zhang. Ammeraal and Zhang propose drawing the chessboard with cartesian coordinates rather than turtle graphics.

I plan to start adding instructional support over the 2020-2021 winter break. In the meantime, feel free to download the source code through the GitHub link shown below.

The code written by me in the com.tjleone.polygons package is licensed under a GNU General Public License. This code relies on an acm library which is licensed under the ACM Java Task Force Software Licensing Agreement. Source code is available at

The educational part of this app is in the actual building of it, but if you'd like to check out the app without compiling it from source code, you can download a Pretty Polygons.msi for Windows or for mac.

Warning about the apps

I'm looking into getting a digital signature for the installers so they'll be recognized as safe to run. However, I don't have one yet. So at this point the downloads are for people who already know me, trust me, and promise not to sue me if anything bad happens after you download and run the app.

When you try to open the Windows version, you'll get a message that says "Windows protected your PC" at the top. If you click the link for more info, a button appears that says "Run anyway".

For the mac version, if you double click on pretty-polygons.jar and get the message "file cannot be opened because it is from an unidentified developer", you have to hold down the Control Key while you click on the file and select "Open".

The Windows installer was built with Advanced Installer.

If anyone can tell me how I might get a free SHA256 digital signature (not a temporary test one), please send an email to



Geometry Resources for 6 and up

Leone Learning Systems, Inc. (LLS) is a North Shore company that provides online courses for kids anywhere and local teaching and tutoring services for students in Chicago and the Northern Suburbs of Chicagoland. LLS also provides a free geometry software package for children age 6 and up, and free resources for teachers and parents. This site includes information about tutoring and classes provided, learning activities for kids, lesson plans, and ongoing software and curriculum research and development efforts.