## Girls’ Angle Bulletin, Volume 9, Number 4

Volume 9, Number 4 begins with an interview with Oberlin’s Andrew and Pauline Delaney Professor of Mathematics Susan Jane Colley, although as has been our practice, we truncate the interview in the electronic version. For the full version, please subscribe!

After a meditation on Miquel’s theorem, find out how a frog fish, dragon, and mathematician end up in the same story with the concluding half of The Mountain Clock, a fictional math story about an ancient city that adopted a 32-hour day.

Anna manages to prove a theorem she has been leading up to ever since Prof. Judy Walker suggested some exercises involving polynomials over the finite field with 2 elements.

Image courtesy of Heidi Hurst

Next comes a neat application of mathematics to disaster recovery.  Harvard University undergraduate Heidi Hurst spent a summer using math to figure out how to find optimal locations for Disaster Recovery Centers.  She explains her work in a two-part Math In Your World series.

Emily and Jasmine continue their exploration of nice triangles and establish a direct link between integer-sided triangles with perimeter p and partitions of p – 3 into parts with sizes 2, 3, and 4.

We conclude by unraveling some secrets of a marvelous recurrence relation created by one of our 11-year-old members.

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!