Not worth the effort

According to an article published a couple of months ago by some British statisticians, the average bank robber in the U.S. gets away with approximately 4,000 dollars.  So to make even a vaguely reasonable living, a hood would have to plan and execute (and avoid subsequent capture) 9 or 10 heists a year.  Doesn't really seem worth it.  Now, according to the same study, an equivalent British bank robber will do a bit better-- an average of nearly 20 grand.  Still, that's a couple of jobs a year for the rest of your life, and bank robbery usually doesn't come with dental.

You might get a company car, though, if you consider the getaway vehicle you carjacked.

Word For The Day -- Crossfoot

In a spreadsheet, you have the traditional option of summing up a series of numbers in a column, but it will also offer you the option to sum up numbers arranged horizontally in a row.

Today I learned that this (in some circumstances) has its own name-- to wit: crossfooting, which you would already have guessed if you read the title of this post.

Hey, I'm not writing these to create suspense, you know.

So anyway, apparently the traditional summing of entries in a column is or at least was called "footing" in accountancy circles.  If you have several columns that break down figures into various categories, with a running total at the end, a good accountant will add up the individual column totals and check it against the running total.  So after you've footed down, you foot sideways in order to cross check your results.  Viola!  Crossfooting.

How to construct a pentagon

Start with a perfect circle.  Find the center, and draw a radius (a straight line between the center and the edge of the circle).  Call the radius R1.  This point on the circumference will be your first point of the pentagon-- call it P1.
Draw another radius perpendicular to the first one.  Call it R2.  Find the point halfway along this radius, and put a temporary mark there.  Draw a line between that mark and P1.  Call this line L1. 

Now, and this is the trickiest part to do without a ruler and protractor, draw a line bisecting the angle between the new line L1 and R2, and put another mark where it intersects R1.  You may have to read that sentence a couple of times, unless you consult the illustration I'm going to shamelessly crib off Wolfram MathWorld and copy below.

Next, draw a line from this new mark perpendicular to R2 out to the edge of the circle.  Where it hits will be your second point of the pentagon.  Call it P2.

Erase all of the incidental interior lines, and then repeat this sequence of steps three more times, each time using the new P point (and its associated radius) as your starting point.  Connect all the Ps, and you'll have a regular pentagon.

Of course, if you have the protractor you need to properly bisect the angle in paragraph three, you can just measure out the 72 degree angles you need for the points, but where's the fun in that?  Also, there's probably some way to bisect an angle without a protractor, but I don't know what it is.