Question

minta tolong dibantu buat besok​

Answer 1

Jawaban:

1) Krucut

d = 16 cm

r = 16 : 2

= 8 cm

t = 15 cm

s = √r² + t²

s = √8² + 15²

s = √ 64 + 225

s = √289

s = 17 cm

V = ⅓ x π x r x r x t

V = ⅓ x 3,14 x 8 x 8 x 17

V = 1.138,77 cm

2) Krucut

V = 8.316 cm³

t = 18 cm

π = 22/7

V = ⅓ x π x r x r x t

8316 = ⅓ x 22/7 x r² x 18

8316 = 22/21 x 18 x r²

8316 = 396/21 x r²

8316 = 18,86 x r²

r² = 8316 : 18,86

r² = 440,9 = 441

r = √441

r = 21 cm

s = √r² + t²

s = √21² + 18²

s = √441 + 324

s = √765

s = 27,65 cm

Ls = π x r x (s + r)

Ls = 22/7 x 21 x ( 27,65 + 21)

Ls = 22 x 3 x 48,65

Ls = 66 x 48,65

Ls = 3.210,9 cm²

3) Luas Alas = 154 cm²

π = 22/7

s = 25 cm

Luas alas = π x r x r

Luas alas= π x r²

154 = 22/7 x r²

r² = 154 : 22/7

r² = 154 x 7 : 22

r² = 49

r = √49

r = 7 cm

t = √s² - r²

t = √25² - 7²

t = √625 - 49

t = √576

t = 24 cm

V = ⅓ x π x r x r x t

V = ⅓ x 22/ 7 x 7 x 7 x 24

V = 154 x 8

V = 1.232 cm³

4) Kll = 62,8 cm

t = 18 cm

π = 3,14

Kll = 2 x π x r

62,8 = 2 x 3,14 x r

62,8 = 6,28 x r

r = 62,8 : 6,28

r = 10 cm

V = ⅓ x π x r x r x t

V = ⅓ x 3,14 x 10 x 10 x 18

V = 1.884 cm³