It may be once or twice a day, when a person needs/wants to find an angle.
Whether doing some work and not being in possession of a protractor, or just taking a passing thought that little bit further - penny protractors could certainly come in handy.
If each penny had a hole in the middle, and a small mark at every 15 degree interval around its circumference - most people would have at least one protractor on them at any time.
-- fridge duck, Dec 12 2005

I like it. And add metric-to-inch-pound conversions to the dollar for ease of reference.
-- Worldgineer, Dec 12 2005


This is but one of a whole class of insufficiently-baked inventions consisting of {currency}{instruments of Math Instruction} including:

Nickel Numbers Dime Dimensions Quarter Questions Half-dollar Hammers

Also note that for the protractor, the 1-oz. Krugerrand has a nice round number (180) of serrations!

Bun for revival of Holey money!

sp: its (circumf...)
-- csea, Dec 13 2005


Sorry about that, bit of confusion over these damned grammatical rules. It are all put back right now.
-- fridge duck, Dec 13 2005


Hey, no problem, I just get fussed about it (and "it's") from time to time!
-- csea, Dec 13 2005


You might try to patent this. Coins and protractors are not novel, but a coin protractor? I doubt that you could get a utility patent for a metal disk to be used as a protractor. I wonder if a coin protractor could have a utility or design patent?

Perhaps there is a whole class of multifunction coin ideas. For example why throw out watch batteries after their use. They could be considered legal tender.
-- geo8rge, Dec 13 2005


//They could be considered legal tender.// but they're ten a penny.
-- po, Dec 13 2005


A brilliant idea! I have been in just such a situation myself. Money should be just as useful to me while in my pocket as it is when going into someone elses.
-- Erfunden, Dec 14 2005


Need one of these. I run into several instances throughout the day where I need a protractor but all I have is a pocket full of change.
-- Jscotty, Dec 14 2005



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