diketahui tiga bola berturut turut memliki jari jari 10 cm, 20 cm, dan 30 cm..tentukan : A. luas permukaan B. volumenya

Jari-jari bola 10 cm, 20 cm, dan 30 cm.


a. Luas permukaan 4 × π × r × r
Jari-jari 10 cm = 4 × 3,14 × 10 cm × 10 cm
= 1.256 cm²

Jari-jari 20 cm = 4 × 3,14 × 20 cm × 20 cm
= 5.024 cm²

Jari-jari 30 cm = 4 × 3,14 × 30 cm × 30 cm
= 11.304 cm²


b. Volume 4/3 × π × r × r ×r
Jari-jari 10 cm = 4/3 × 3,14 × 10 cm × 10 cm × 10 cm=
4.186,6 cm³

Jari-jari 20 cm = 4/3 × 3,14 × 20 cm × 20 cm × 20 cm =
33.493,3 cm³

Jari-jari 30 cm = 4/3 × 3,14 × 30 cm × 30 cm × 30 cm =
113.040 cm³

a. luas permukaan
   bola I =4πr2                             volume=4/3πr3
             =4.22/7.100                               =4/3.22/7.1000
             = 8800/7                                    =88000/21
             =1257,1 cm 2                              =4190,4
  bola II =4.22/7.400                   volum  =4/3.22/7.4000
             =35200/7                                   =352000/21
             =5028,5 cm2                               =1676,9 cm3

 bola III =4.22/7.900                   volume =4/3.22/7.9000               
             = 79200/7                                   =792000/21
             =11314, cm2                              =37714,2