Task of the Week: Rosetta

The Rosetta is located in Erfurt, Germany.

Determine the inner circumference of the rosette. (dyed red). Give the result in meters to two decimals!

To solve the task, one must first consider how to determine the diameter of the circle. This can not be measured in the classical sense. However, it is possible to count the number of stone rows and to get to the diameter by multiplying with the height of a stone. One problem here is that the height of the stones is not uniform and has to be formed through a suitable mean value.