[math-fun] Fwd: gluing a 3-3-3 triangle onto a 3-5-7

28 Sep 2014

      E.g.,In[162]:= triangs[144, 135, 31]

Out[162]= {ArcCos[475/486], ArcCos[-(5/27)], ArcCos[7/18]}

In[144]:= Rationalize[#, 99^-9] & /@ Ratios[%]

Out[144]= {3400276089/412519223, 2/3}
I.e., two of the angles of a 31:135:144 triangle are in ratio 2:3 .
--rwg
---------- Forwarded message ----------
From: Mike Hirschhorn <m.hirschhorn@unsw.edu.au>
Date: Sun, Sep 28, 2014 at 7:10 PM
Subject: RE: gluing a 3-3-3 triangle onto a 3-5-7
To: "billgosper@gmail.com" <billgosper@gmail.com>

Dear Bill,

I wrote something related to this some years ago. Please see
gosper.org/paper166.pdf.
It appeared in the (British) Mathematical Gazette).

Best wishes,

Mike H.

[math-fun] Fwd: gluing a 3-3-3 triangle onto a 3-5-7

Bill Gosper