Ah, volume! 
1) Use the formula of rectangular prism: width x height x length
2) Use the formula of triangular prism: (Base x height x length) ÷ 2
3) Use the formula of cylinder: π x 
 x height
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1)
- width = 5 cm
 - height = 9 cm
 - length = 23 cm
 
width x height x length 
= 5 x 9 x 23 
= 1035
answer: 1035 cubic centimeters
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2)
- Base = 5 in
 - height = 4 in
 - length = 20 in
 
(Base x height x length) ÷ 2
= (5 x 4 x 20) ÷ 2
= 400 ÷ 2
= 200
answer: 200 cubic inches
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3) 
- radius = 5/2 = 2.5 m
 - height = 12 m
 
π x 
 x height
= π x 
 x 12 
= π x 6.25 x 12
= 75π 
= 236 (rounded to neareast whole number)
answer: 236 cubic meters