Find the volume of sphere by Steinmetz solid (mouhefanggai)

Sphere, Volume
The applet show how to construct the equation of volume of sphere by finding the volume of Steinmetz solid. The method is provided by ZuChongzhi who divide the Steinmetz solid into 8 equal parts. Using the applet, the equation of volume of sphere can be done by students. This is my final project of HKIed (The Hong Kong Institute of Education). You need to use Geogebra 5.0 Beta to open it. Best resolution is 1920x1080. Author: Accel Ip
How to find the volume of sphere?