keliling alas sebuah tabung132cm jika tinggi tabung5cm volume tabung adalah

diket keliling alas tabung = 132 cm
         tinggi tabung (t) = 5 cm
ditanya volume tabung=...?
jawab
   keliling alas tabung = 2.πr
                          132  = 2.22/7.r
                      132 x 7 = 2 x 22 x r
                             924 = 44r
                                r = 924/44
                                 r = 21
volume tabung = πr²t
                         = 22/7 x 21 x 21 x 5
                         = 22 x 3 x 21 x 5
                         =  6.930 cm³