Kunci Jawaban Matematika Kelas 9 Halaman 280, 281, 282, 283, Menghitung Luas dan Volume

Lp = 2πr(r + t)
Lp = 2 x 3,14 x 2 (2 + 10)
Lp = 12,56 (12)
Lp = 150,72 m²
V = πr²t
V = 3,14 x 2² x 10
V = 125,6 m³

Tabung F

Lp = 2πr(r + t)
Lp = 2 x 22/7 x 3,5 (3,5 + 20)
Lp = 22 (23,5)
Lp = 517 dm²
V = πr²t
V = 22/7 x 3,5² x 20
V = 770 dm³

Soal 2. Panjang dari unsur tabung, yaitu:

Contoh Jawaban:

a. V = πr²t

t = V : (πr²)
t = 600π : (π x 10²)
t = 600π : (100π)
t = 6 cm

b. Lp = 2πr(r + t)

(r + t) = Lp : 2πr
(5 + t) = 120π : 2π5
(5 + t) = 120π : 10π
(5 + t) = 12
t = 12 - 5 = 7 cm

c. V = πr²t