Jawab:

Luas ≈ 675.1 cm²
Volume ≈ 1360 ⅔ cm³

Penjelasan dengan langkah-langkah:

(E). Diketahui:
r = 5 cm
t = 10 cm
b = 12 cm

Cari s
s² = r² + b²
s² = 5² + 12²
s² = 25+144
s² = 169
s = √169
s = 13 cm
-------------------------

Dicari: luas permukaan

(i) Selimut kerucut
π×r×s

(ii) Selimut tabung
2×π×r×t

(iii) Setengah bola
2×π×r×r

Maka Luas = (i)+(ii)+(iii)
Luas =
π×r×s + 2×π×r×t + 2×π×r×r
π×r×(s+(2×t)+(2×r)) =
π×r×(s+(2×(t+r))) ≈
3.14×5×(13+(2×(10+5))) ≈
15.7×(13+(2×15)) ≈
15.7×(13+30) ≈
15.7×43 ≈
≈ 675.1 cm²

-------------------------

DICARI VOLUME

(a) Volume kerucut =
π×r×r×b×⅓

(b) Volume tabung =
π×r×r×t

(c.) Volume 1/2 bola =
⅔×π×r×r×r

Volume = (a)+(b)+(c) =
π×r×r×b×⅓ + π×r×r×t + ⅔×π×r×r×r
= πr² × ((b×⅓) + t + (⅔×r))
≈ 3.14×5² × ((12×⅓) + 10 + (⅔×5))
≈ 3.14×25 × (4 + 10 + ¹⁰/₃)
≈ 78.5 × (14 + ⁹/₃ + ⅓)
≈ (78 + ½) × (14 + 3 + ⅓)
≈ (78 + ½) × (17 + ⅓)
≈ (¹⁵⁶⁺½) × (⁵¹⁺⅓)
≈ (¹⁵⁷/₂) × (⁵²/₃)
≈ 157 × (²⁶/₃)
≈ ⁴⁰⁸²/₃
≈ ⁴⁰⁸⁰/₃ + ⅔
≈ 1360 + ⅔
≈ 1360 ⅔ cm³

<(7o7)>