sebuah Kerucut Keliling Alasnya 88cm, dan tingginya 48 cm tentukan a. Luas selimut b. Luas permukaan c. Volumenya

Ka= 88 cm
t= 48 cm
Ditanya= LS?, LP?, dan V?

K= πd
88= 22/7 x d
d= 88/22/7
d= 88 x 7/22
d= 4 x 7
d= 28 cm > r= 14 cm

S²= r²+t²
S²= 14²+48²
S²= 196+2304
S= √2500
S= 50 cm

LS= πrs
LS= 22/7 x 14 x 50
LS= 22 x 2 x 50
LS= 44 x 50
LS= 2200 cm²

LP= πr(r+s)
LP= 22/7 x 14(14+50)
LP= 22 x 2(64)
LP= 44 x 64
LP= 2816 cm²

V= ⅓ x La x t
V= ⅓ x 22/7 x 14 x 14 x 48
V= 22 x 2 x 14 x 16
V= 44 x 14 x 16
V= 616 x 16
V= 9856 cm³

Stay focus and be the best, Buddy :)

Kelas 9 Matematika
Bab 2 - Bangun Ruang Sisi Lengkung

Kerucut
Ka = 88 cm
t = 48 cm

K = 2πr
88 = 2 × 22/7 × r
88 = 44/7 × r
r = 88 × 7/44
r = 14 cm

s = √(r² + t²)
s = √(14² + 48²)
s = √(196 + 2.304)
s = √2.500
s = 50 cm

a. Luas selimut
Ls = πrs
Ls = 22/7 × 14 cm × 50 cm
Ls = 2.200 cm²

b. Luas permukaan
Lp = πr(r + s)
Lp = 22/7 × 14 cm (14 cm + 50 cm)
Lp = 44 cm × 64 cm
Lp = 2.816 cm²

c. Volume
V = 1/3 × πr²t
V = 1/3 × 22/7 × 14 cm × 14 cm × 48 cm
V = 9.856 cm³