Jawaban:

17. B

18. B

19. B

Penjelasan dengan langkah-langkah:

17. 4 x phi x r²

= 4 x 3,14 x 10 x 10 x 1/2

= 4 x 314/100 x 100 x 1/2

= 4 x 314 x 1/2

= 1256 / 2

= 628 cm²

18. 38.808 liter = 38.808.000 cm³

vol = 4/3 x phi x r³

38.808.000 = 4/3 x 22/7 x r³

38.808.000 x 3/4 x 7/22 = r³

9.261.000 = r³

r = 210 cm

19. vol tabung + vol balok

= (phi x r² x t x 1/2 ) + (p x l x t)

= (22/7 x 7 x 7 x 20 x 1/2 ) + ( 20 x 14 x 10 )

= 1540 + 2800

= 4340 cm³

semoga membantuu

kasi jawabn terbaik ya :))))