You need to utilize the volume formula for an irregular prism in order to find the volume of a hexagonal prism. The volume of an irregular prism equals the area of the base times the height of the prism. To calculate the area of a hexagon, you need to divide the hexagon into six separate triangles. Once you perform this area calculation, you then need to multiply the result by the height of your prism.

Find the length of one side of the hexagon. For example, assume the length of one side is 6 inches.

Square the length you measured, then multiply the result by 0.86602. In the example, 6 inches squared equals 36, then 36 times 0.86602 equals 31.17672.

Multiply the result in Step 3 by six. In the example, 31.17672 times six equals 187.06032 inches squared. This is the area of the hexagon.

Measure the height of the hexagon, then multiply the amount by the result from Step 4. In the example, assume a height of two inches. 187.06032 times two equals 374.12064. So the volume of the hexagonal prism is 374.12064 cubic inches.
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