Answer: 198
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Step-by-step explanation:
First we need the area of the triangular face.
area = base*height/2
area = 9*11/2
area = 99/2
area = 49.5 square cm
Multiply this triangular area with the depth of the prism.
volume = (area of base face)*(depth of prism)
volume = (49.5 sq cm)*4 cm)
volume = 198 cubic cm
The volume units "cubic cm" can be written as

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Another way to think about it:
Consider a box that is 11 cm by 9 cm by 4 cm
The volume would be 11*9*4 = 396 cubic cm
That's for a rectangular prism, but we want a triangular prism. The volume will be half that at 396/2 = 198 cubic cm
If we had two identical triangular sandwiches, putting them together forms a full rectangular prism.