Forest and Trees for Dummies

3-4-5 right triangle

If you've ever taken calculus, you're familiar with the phrase "it's intuitive." Being able to solve problems intuitively is why many natural mathematicians are so bad at teaching the subject. We don't know whether Barrett James, Jr., of Suite.io is a natural in the building trades or not, but it's for sure he can't teach the subject, perhaps because he can't see the forest for the trees. For an idea of this form of selective blindness, check out the story (Suite's cutesy name for its content is a "story") he called "An Easy Method to Square Foundations of Free Standing Structures."¹

Barrett's problem here is that he left out a key step. His "easy method" – which addresses foundation layout, not the foundations themselves – is to place the four corners of your structure and then measure the diagonals. The logic is simple: if the pairs of opposing sides are the same length but the two diagonals aren't identical, the shape is a parallelogram instead of a rectangle. Here's how he says to perform this step: "Measure out the distances using a marker of some sort for each corner. Anything will work, this is just a temporary step. Next, using a long tape measure, check the distances at an angle between two opposite corner markers, and compare to the distances between the other two. If the distances are roughly equal, you can proceed to the next step. If not, adjust them the appropriate distance, always keeping the side lengths the same until the corners are close in distance apart."

 The "next step" he mentions is to stake the corners. Ummm, yeah....

Our staff carpenter has built a couple of outdoor structures in his time, and he says that Mr. James, Jr., left out a critical step: squaring those first two corners before laying out all four sides. If you square the corners on both ends of one side, you are very likely to achieve Barrett's same-diagonals situation on the first try. If you don't, you'll find yourself fumbling around trying to figure out which side you must to move in which direction to correct the shape.

Squaring those corners with a 3-4-5 right triangle is a simple process practiced by builders every day - but Barrett overlooks this critical step in laying out a foundation. He doesn't mention it at all, even though he mentions the Pythagorean theorem! We think that proves Barrett's a worthy recipient of our Dumbass of the Day award.

¹ This website is now defunct, and archive.org's Wayback machine never made a copy of the post. Oh, well, no loss...

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