1.sebuah tabung tingginya 15 cm dan jari jarinya 14 cm.tentukan luas pernukaan tabung... 2. jika luas selimut tabung 1540cm kuadrat dan tinggi tabung 35cm. tent

1. LP = 2 x phi x r ( r + t )
= 2 x 22/7 x 14 ( 14 + 15 )
= 2 x 22/7 x 14 x 29
= 2.552 cm2

2. LS = 2 x phi x r x t
1540= 2 x 22/7 x r x 35
1540= 220 x r
r = 1540 : 220
r = 7

#maafkalosalah.

1)
t = 15 cm
r = 14 cm
Lpt = ....???

Lpt = (2 × phi × r^2) + (2 × phi × r × t)
Lpt = 2 × phi × r × (r + t)
Lpt = 2 × 22/7 × 14 × (14 + 15)
Lpt = 88 × 29
Lpt = 2552 cm^2

2)
Lst = 1540 cm^2
t = 35 cm
r = ...???

Lst = 2 × phi × r × t
1540 = 2 × 22/7 × r × 35
1540 = 220 × r
r = 1540/220
r = 7 cm