We now substitute into the ConeVol formula for r and R our expressions which involve theta only to obtain the volume of the cone in terms of theta alone.

Input := 


CVol[theta_] = ConeVol/.solR[[1]]/.solr[[1]]

Output =


   3                3

-(L  (-2 Pi + theta)  

                   2

                  L

     Sqrt[------------------- - 

                            2

          (2 + 2 Pi - theta)

           2                2

          L  (-2 Pi + theta)

       -------------------------]) / 

           2                   2

       4 Pi  (2 + 2 Pi - theta)

        2                   3

  (24 Pi  (2 + 2 Pi - theta) )