Prism Volume for Dummies

Volume of a Prism

Although we're on record as saying that introducing a post by quoting the dictionary definition of a critical term is... well, poor construction; we must assume that a legitimate freelancer faced with an unfamiliar term in the course of a job will look it up or ask an expert for the meaning. Apparently that's what eHow.com's one and only Jonae Fredericks did when faced with the new-to-her word "prism." Yep, the concept apparently never came up in cosmetology school, but Jonae still courageously tackled the question "How to Calculate the Volume of a Prism¹" for the mother site. Oh, the humanity...

Jonae's lack of suitability to address the question is clear from the first sentence of her introduction:

"The volume of any type of mass can be measured by how much space it takes up. Volume is most often measured by using some kind of container and taking stock of how much it can hold."

Yeah, sure: talk about a circular definition! And that "most often measured by" bull? Does Fredericks think we're all Archimedes? What a buffoon!  Jonae then asked Google for their definition of prism, which apparently confused her by noting that a prism's ends are "similar, equal, and parallel rectilinear figures." That word "rectilinear" looked enough like "rectangle" that Fredericks proceeded to inform her audience that "The volume of a prism is measured as a three dimensional object, with mass, as explained in the following steps. The formula for such an equation is: v=L x W x H."

But wait, Jonae: that's the formula for the volume of a rectangular solid, not a prism... Had Fredericks looked up the definition of "rectilinear," she would have learned that it means any shape whose sides are straight lines. In other words, the ends of a prism are not necessary rectangles, they can be triangles, hexagons, pentagons, and number of sides; and regular or irregular. "Informing" her readers that the general formula for the volume of a prism is simply "L x W x H" is, well, it's stupid.

No: the general formula for the volume of a prism is the product of its cross-sectional area (area of one of the ends) and its height. Jonae's "answer" fits one, and only one, shape of a near-infinite number of prism shapes. And the reason why she thought this was sufficient? If you google "volume of prism" the first result you see says, "A rectangular prism has three dimensions..." Clearly, Fredericks failed to perform the further research needed to learn that there are more than just rectangular prisms. We think that's plenty of reason to hand Jonae today's Dumbass of the Day award. You?

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was ehow.com/how_2297494_calculate-volume-prism.html

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