Hitunglah luas permukaan bangun ruang berikut.

A. Lp = 4× phi × r ×r
Lp = 4× 3,14 × 50 ×50
Lp = 31,400 cm persegi

b. Lp = phi×r (s+r)
Lp = 3,14 × 9 (12+9)
Lp = 28,26 (21)
Lp = 593,46 cm persegi

c. Lp = 2 × phi × r (r+t)
Lp = 2 × 3,14 × 0,75 (0,75 + 6)
Lp = 4,71 (6,75)
Lp = 31,792 cm persegi

A. Lp bola=4phi r^
=4.3,14.10.10
=1256
b. Lp kerucut=phi r^ +phi r s
=3,14 . 9 . 9+3.14 . 9 . 15
=254,34+423,9
=678,24