pake cara yaaaaaaaaaaaaa

28. V kubus + V balok
=S^3 + p×l×t
=20^3 + 50×20×20
=8000 + 20000
=C 28000 mm^3

29. V tabung
=phi×r^2×t
=22/7×7×7×12
=C 1848

30. Luas permukaan kubus
=6×S^2
=6×18×18
=D 1944

Semoga membantu ^_^

28. V kubus + V balok =S^3 + p×l×t =20^3 + 50×20×20 =8000 × 20000 =C 28000 mm^3
29. 22/7.7^2.12=22.7.12
=1848
=C.1848
30. Luas permukaan kubus =6×S^2 =6×18×18 =D.1944