Friday, May 22, 2009

We were right...

It is definitely the first pottery kiln.  A major discovery, since this is the first English style kiln excavated by archaeologists from the country between Denver and the Pacific coast of California.  Maybe even as far east as Tennessee, Minnesota, or Kentucky.

Renée and Samantha are still working to expose the arc of brick:
Sam is happy to be cleaning the sidewalls in preparation for a photo!

We spent lunch talking about how to calculate the diameter of a circle when you can only measure a chord along the arc.  This is a particular question for the mathletes out there.  I've worked out a solution in the tradition of pragmatic field archaeology, but if somebody thinks they can be more accurate, let me know!

The chord is 1.80 meters long measured from the outside edge.  Making a 90° angle and measuring at 0.90 meter gives a triangle side that measures 0.23 meter.  A real world word problem!
email or post your solution!  Show your work for partial credit...

1 comment:

  1. Given that c is a straight line between two points on the circumference of a circle--X and Z--which is called the cord, the curved line would be called arc XZ.

    Assuming you know c (not XZ) and m--the height of the arc created by the chord--then the formula would be:

    r = (m² + ¼c²)/2m

    Hooray for the internet!