tinggi tabung 1½ ×jari jari alas. luas selimut tabung 942cm³ maka volume tabung adalah

t = 1 1/2 × r
t = 3/2 × r
Lst = 942 cm^2
Vt =....???

Lst = 2 × phi x r × t
942 = 2 × 3,14 × r × (3/2 × r)
942 = 9,42 × r^2
r^2 = 942/9,42
r^2 = 100
r = V100
r = 10 cm
t = 3/2 × r
t = 3/2 × 10
t = 15 cm

Vt = 1/3 × phi × r^2 × t
Vt = 1/3 × 3,14 × 10^2 × 15
Vt = 1/3 × 3,14 × 100 × 15
Vt = 1570 cm^3

Jadi volume tabung adalah 1570 cm^3