# Copie de Circumference of Circles

- Author:
- R. Bayle, Anthony OR 柯志明

- Topic:
- Circle

(See http://www.geogebratube.org/material/show/id/8222 for anothernew version.)
Drag the green point to appropriate position to measure the diameter of the circle.
Drag the red point P to straighten the circumference. Divide the scale of the ruler to measure its length to

**two decimal places**. Use the Zoom In, Zoom Out and Move tools if necessary. Calculate the values of c/d. What do you discover?Anthony OR. GeoGebra Institute of Hong Kong.

## New Resources

## Discover Resources

Download our apps here: