## Girls’ Angle Bulletin, Volume 7, Number 4

The cover features a planar configuration by Leah Berman, associate professor of mathematics at the University of Alaska Fairbanks.  There are 240 lines and 240 points arranged so that each line contains 6 of the 240 points and each point sits on 6 of the 240 lines. More images of planar configurations by Leah and Nadine Alise can be found in Mathematical Buffet.

This issue’s interview is with University of Oregon Professor Emerita Marie Vitulli.  In this first part of a 2 part interview, we learn about Prof. Vitulli’s field and how she got into mathematics.

Special thanks to Professor Emeritus Thomas Moore for contributing a problem about Pythagorean triples.  If you haven’t heard of Pythagorean triples, Prof. Moore gives a brief introduction and more challenges in Pythagorean Triples Challenge.

Angles pervade much of this issue.  In Learn By Doing, Addie Summer covers the basic of angle measure.  Then, Lightning Factorial follows Emily and Jasmine as they use angles to design a stained glass window.  Finally, in this issue’s Math In Your World, I write about one of John and Jane Kostick’s latest creations, which they dub the Quintetra Assembly.  To compute the necessary angles needed to create a wood sculpture for this amazing polyhedron, several angles must be computed.  In this article, I sketch how to determine these angles and include a net, courtesy of the Kosticks, for Jane’s Quintetra block, 30 of which can be used to build a model of the Quintetra Assembly.

Finally, Anna continues her investigation of x to the x.

We hope you enjoy it!

Finally, a reminder: when you subscribe to the Girls’ Angle Bulletin, you’re not just getting a subscription to a magazine. You are also gaining access to the Girls’ Angle mentors.  We urge all subscribers and members to write us with your math questions or anything else in the Bulletin or having to do with mathematics in general. We will respond. We want you to get active and do mathematics. Parts of the Bulletin are written to induce you to wonder and respond with more questions. Don’t let those questions fade away and become forgotten. Send them to us!

We continue to encourage people to subscribe to our print version, so we have removed some content from the electronic version.  Subscriptions are a great way to support Girls’ Angle while getting something concrete back in return.  We hope you subscribe!