Hitung luas permukaan bangun diatas! (phi = 22 /7)

Tabung a = 22/7 × Rusuk × Rusuk × Tinggi
= 22/7 × 7 × 7 × 5
= 22 × 35
= 770
Tabung b = 22/7 × Rusuk × Rusuk × Tinggi
= 22/7 × 14 × 14 × 5
= 22 ×2 × 14 × 5
= 44 × 70
= 2640
Jadi, Tabung a + tabung b
= 770 + 2640
= 3430