To be fair, Homer makes the exact same mistake in the original context. And that mistake was in turn referencing the error the Scarecrow made in the Wizard of Oz.

Someone is confusing a square and a square root.

You can have a 3 4 5 right triangle because 9 + 16 = 25. This post suggests that the square root of 3 (which is about 1.7) + the square root of 4 (which is 2) is equal to the square root of 5 (which is about 2.2)

If you're going to shitpost, pass high school math then shitpost.