Question

Luas selimut kerucut 816,4 cm2.Jika panjang garis pelukis 26 cm,Hitunglah volume kerucut!(π=3,14)
Tolong jawabannya yah?:)

Answer 1

v = πrs
816,4 = 3,14 x r x 26
816,4 = 81,64 x r
r        = 816,4
           81,64
r       = 10 cm

tinggi = √26² - 10²
         = √676 - 100
         = √576
         = 24

V = 1/3πr²t

V = 1/3 x 3,14 x 10 x 10 x 24
V = 1 x 3,14 x 10 x 10 x 8
V = 2.512 cm³

Answer 2

Dik:
Lselimut = 816,4 cm²
s = 26 cm
Dit:
V = ... ?
Jawab:
Lselimut = π r s
816,4 = 3,14 r 26
816,4 = 81,64 r
r = 816,4/81,64
r = 10 cm

t = √ s² - r²
t = √ 26² - 10²
t = √ 676 - 100
t = √576
t = 24 cm

Jika sudah diketahui t & r maka, V = 1/3 π r² t
V = 1/3 × 3,14 × (10)² × 24
V = 1/3 × 3,14 × 100 × 24
V = 8 × 314
V = 2.512 cm³