luas selimut tabung mempunyai volume 770cm3, diameter 7cm, dan v= 22/7 adalah......

volume = 770
luas alas = πr²
= 22/7 × 7/2 × 7/2
= 77/2

tinggi = vol. ÷ L.alas
= 770 ÷ 77/2
= 20

luas tabung
= 2×luas lingk. + (kel. lingk.×tinggi)
= 2×77/2 + 22/7×7×20
= 77 + 440 = 517 cm²

luas selimut
= kel. lingk. × tinggi
= 22/7 × 7 × 20
= 440 cm²

v = 1/4 × phi × d^2 × t
770 = 1/4 × 22/7 × 7 × 7 × t
770 = 38,5 × t
t = 770 / 38,5
t = 20 cm
luas selimut tabung = phi x d x t
= 22/7 × 7 × 20
= 440 cm^2