You can find the volume of a solid of revolution the same way you calculate integrals in GeoGebra . 
     GeoGebra Instruction 1
CAS     under         View     in         Menu.         Integral(<Function>, <Start x-Value>, <End x-Value>)
in CAS. For <Function>, fill in  
   pi <your expression>^2 
For <Start x-Value> and <End x-Value>, type in the limits of integration.         Press Enter.