IN Sky and Telescope of September, under the heading “Saluting an Astronomer”, Joseph R. Habes has an article which describes the method adopted by Eratosthenes for measuring the circumference ...

Hey Ray: Using Pi to measure hat size There is Pi all around us, in ways you may not have seen before. If you remember from school, Pi is the ratio of a circle's circumference to its diameter. It ...

How do you find the area of a circle? Can you measure the area of a circle and use that to find a value for Pi?