Hitunglah luas tabung jika r=20 t =25 dan phi=22/7

Luas Bangun : 2La + Ka. t
Lp = 2 × πr^(2) + 2πr t
Lp = 2 × 22/7 × 20 × 20 + 2 × 22/7 × 20 × 25
Lp = 17.600 / 7 + 22.000/7
Lp = 39.600 / 7
Lp = 5.657, 142

L.Tabung= 2.phi.r(r+t)
= 2.3,14.20(20+25)
= 314.45
=14.130 cm persegi