The Diagonal of a Square for Dummies

The question said "measure"...

Over the years, we've found that reading the short biographies of contributors to what used to be Demand Media Studios (former parent of eHow.com, SFGate, Livestrong, etc., now known as Leaf Group) can be very revealing. Take today's DotD, Jana Sosnowski: her little bio mentions (of course) a degree in journalism, along with a stint as a "curriculum writer for a math remediation program." Based, however, on "How to Measure the Length of the Diagonal Line of a Square" at Sciencing.com, however, it appears that she might need some math remediation herself.

Sosnowski may have been flummoxed by the demands of Demand Media, since she opines in her introduction that

"Knowing the length of the diagonal will help you find dimensions of the two right triangles formed within the square. While you can measure a diagonal with a ruler, you can also use the Pythagorean theorem to find its length."

The second statement is demonstrably true – except that if you don't already know the "dimensions of the two right triangles," you sure as heck can't use the Pythagorean Theorem to find the length of the diagonal... idiot!
Jana goes on to explain, at some length, how to use the Pythagorean Theorem in this exercise. Since she was stuck with a minimum word count, she did get rather carried away a time or two, such as this statement:

"A square split in half diagonally forms two right triangles. Each of these triangles has two equal legs, or sides, that are the same length as the sides of the square."

We think that's a rather clumsy way to say that the legs of the triangle are the sides of the square. but what do we know? We don't have journalism degrees... anyway, Sosnowski goes through a somewhat convoluted example for calculating the diagonal of a square with sides equal to five. We'll be honest and say that, verbosity and all, she gets the right answer. Oddly, however, she never mentions that there are two diagonals, and they are the same length – if they aren't, the polygon isn't a square!

Except for one thing: the OQ wanted to know "How to Measure..." – and Sosnowski blew right past that concept in her introduction. The only thing that keeps this from being a complete FUBAR is that Sosnowski did a somewhat better job of describing the calculation than did the original by Julie Richards... but that doesn't means she isn't still the Dumbass of the Day!

copyright © 2017-2022 scmrak

MM - GEOMETRY