Luas selimut tabung 220 cm2

A.
L sel = K alas × t
220 = 2nr × t
220 = 2 × 22/7 × r × 7
r = 5

B.
L tab tanpa tutup = L sel + L alas
= 220 + nr^2
= 220 + (3,14 × 5 × 5)
= 298,5