rumus diameter tabung tinggi 28 diameter 18 adalah

                     no1                                                                                                                  3,14 * setengah dari 18= 9   jadi,3,14*9*9= 254,34 *28=712,152                         no2                                                                                                                         22 per 7= *28*28=28/7=4*28 =112*18 =2016