volume kerucut yang keliling alasnya 44 cm, garis pelukisnya 25 cm, dengan phi=22/7

Kelas 8 Matematika
Bab Bangun Ruang

Keliling = 44
2 . π . r = 44
2 . 22/7 . r = 44
r = 44 . 7/44
r = 7 cm

t = √(s² - r²)
t = √(25² - 7²)
t = √(625 - 49)
t = √576
t = 24 cm

Volume
= 1/3 . π . r . r . t
= 1/3 . 22/7 . 7 . 7 . 24
= 1.232 cm^3

Keliling alas = πd
44 = 22/7 x d
d = 44 : 22/7
d = 44 x 7/22
d = 14 cm

r = 1/2d
= 7 cm

t = √s² - r ²
= √ 625 - 49
= √576
= 24 cm

Volume Kerucut
=1/3 π r² t
= 1/3 x 22/7 x 49 x 24
= 22/21 x 49 x 24
= 1232 cm²