Jika suatu kerucut diketahui luas alasnya 154 cm² sedangkan tingginya 24 cm berapa luas selimut kerucut?

Mapel : Matematika
Bab : Bangun ruang

Luas alas = π x r²
  154 cm²  = 22/7 x r²
              r² = 154 : 22/7
              r² = 154 x 7/22
              r² = 49
              r  = √49
              r  = 7 cm

s = √t² + r²
   = √24² + 7²
   = √576 + 49
   = √625
   = 25 cm

Luas selimut kerucut
= π x r x s
= 22/7 x 7 cm x 25 cm
= 22 cm x 25 cm
= 550 cm²

Bangun Ruang Sisi lengkung

L alas = Lingkaran

L = 22/7 × r^2
154 = 22/7 × r^2
154/22/7 = r^2
154 × 7/22 = r^2
49 = r^2
[tex] \sqrt{49} = r[/tex]
7 = r


Cari Garis Pelukisnya


[tex] s = \sqrt{r ^{2} } + t ^{2} [/tex]
[tex]s = \sqrt{7 ^{2} } + 24 ^{2} [/tex]
[tex]s = \sqrt{49} + 576[/tex]
[tex]s = \sqrt{625} [/tex]
[tex]s = 25 \: cm[/tex]


L Selimut = 22/7 × r × s
L = 22/7 × 7 × 25
L = 22 × 25
L = 550 cm^2