Update Kunci Jawaban Soal Harian Matematika Kelas 9 SMP Halaman 293 Kurikulum 2013, Latihan 5 2

1. Tentukan luas permukaan dan volume dari bangun kerucut berikut (lihat gambar di buku).

a. s = √(r² + t²)
s = √(4² + 12²)
s = √(16 + 144)
s = √160 = 4√10

Lp = πr(r + s)
Lp = 3,14 x 4(4 + 4√10)
Lp = 12,56(16,65)
Lp = 209,11 cm²

V = ⅓ πr²t
V = ⅓ x 3,14 x 4² x 12
V = 200,96 cm³

b. t = √(s² - r²)
t = √(10² - 6²)
t = √(100 - 36)
t = √64 = 8

Lp = πr(r + s)
Lp = 3,14 x 6(6 + 8)
Lp = 18,84(14)
Lp = 263,76 cm²

V = ⅓ πr²t
V = ⅓ x 3,14 x 6² x 8
V = 301,44 cm³

c. s = √(r² + t²)
s = √(6² + 10²)
s = √(36 + 100)
s = √136 = 2√34

Lp = πr(r + s)
Lp = 3,14 x 6(6 + 2√34)
Lp = 18,84(17,66)
Lp = 332,75 cm²

V = ⅓ πr²t
V = ⅓ x 3,14 x 6² x 10
V = 376,8 cm³