tabung berjari jari alas 20 cm dan tinggi tabung 7 cm hitunglah: luas permukaan tabung tanpa tutup

Πr^2+2Πrt
=3,14×20×20+2×3,14×20×7
=2135,2 cm^2

r = 20 cm
t = 7 cm

La = phi × r^2
La = 3,14 × 20^2
La = 1256 cm^2

Ls = 2 × phi × r × t
Ls = 2 × 3,14 × 20 × 7
Ls = 879,2 cm^2

Lttt = La + Ls
Lttt = 1256 cm^2 + 879,2 cm^2
Lttt = 2135,2 cm^2