Tolong bsok di kumpul Please guys yg niat aja

Tolong bsok di kumpul
Please guys yg niat aja

Tolong bsok di kumpul
Please guys yg niat aja

2 a.
V. kerucut = 1/3 × phi × r × r × t
300 phi = 1/3 × phi × 10 × 10 × t
300 = 100/3 × t
t = 300 ÷ 100/3 = 300 × 3/100 = 3×3 = 9 m

2 b.
V. kerucut = 1/3 × phi × r × r × t
120 phi = 1/3 × phi × r × r × 10
120 = 10/3 × r × r
${r}^{2} = 120 div frac{10}{3} = 120 times frac{3}{10} = 12 times 3 = 36 \ r = sqrt{36} = 6 : m$

2 c.
L. permukaan kerucut =
$pi {r}^{2} + pi rs$
$180pi = pi times {8}^{2} + pi times 8 times s \ 180 = 64 + 8s \ 8s = 180 - 64 = 116 \ s = 116 div 8 = 17 : cm$

tinggi =
$sqrt{ {s}^{2} - {r}^{2} } = sqrt{ {17}^{2} - {8}^{2} } = \ sqrt{289 - 64} = sqrt{225} = 15 : cm$

2 d.
jari – jari =
$sqrt{ {s}^{2} - {t}^{2} } = sqrt{ {15}^{2} - {12}^{2} } = \ sqrt{225 - 144} = sqrt{81} = 9: dm$

2 e.

L. permukaan kerucut =
$pi {r}^{2} + pi rs$
$225pi = pi times {r}^{2} + pi times r times 16 \ 225 = {r}^{2} + 16r \ {r}^{2} + 16r - 225 = 0 \ (r + 25)(r - 9) = 0 \ r = - 25 : dan : 9 \karena : r > 0, : maka : r = 9 : cm\$

tinggi =
$sqrt{ {s}^{2} - {r}^{2} } = sqrt{ {16}^{2} - {9}^{2} } = \ sqrt{256 - 81} = sqrt{175} = 5 sqrt{7} : cm$

2 f.
V. kerucut = 1/3 × phi × r × r × t
150 phi = 1/3 × phi × 15/2 × 15/2 × t
150 = 75/4 × t
t = 150 ÷ 75/4 = 150 × 4/75 = 2×4 = 8 cm