31-34 tolong dijawab pake cara

31)Volume=1/2×a×t×t prisma
=1/2×15×20×30
=4500 cm3

32)Volume=π×r×r×t
=22/7×14×14×15
=9240 cm3
=9240/1000
=9,24 liter
=9,24×2/3
=6,16 liter