Measuring Tree Height for Dummies

Using trigonometry to measure height

If you look through the 517 other entries in our Antisocial Network tally of daily dumbasses, you may notice that we often mention eHow.com's minimum word count as one of the reason we catch their contributors being stupid. Most of the time it's because they've padded short answers to meet the MWC; sometimes it's because they just can't seem to shut up. Today's the latter: we found Amelia Allonsy (already a two-time winner) padding her answer to the VERY simple question "How to Judge the Height of a Tree"¹ for the Demand Media site SFGate.com. Note that there are several ways to do this, two or three of which could easily have been discussed in a space of 300 words – Allonsy took 450 words to discuss one – and in all honesty, she did a rather poor job.

Amelia's solution takes five steps. Well, we suppose that's OK if you feel you must break it down into

1. Measure the length of the tree's shadow
2. Measure the length of your own shadow
3. Measure your own height
4. Multiply the length of the tree's shadow times your actual height, multiplying the measurements in inches.
5. Divide the figure you got previously by your shadow's length, using inches for all the figures.

We're still not certain why she found it necessary to convert everything to inches, but if you're innumerate we suppose that would work (though for the truly innumerate, she should have probably provided the conversion factor of 1 foot = 12 inches). Whatever the case, we think it would have been more efficient to simply tell the reader to Measure the length of the tree's shadow, X Measure the length of the shadow, Y, of an object of known height, Z Divide X by the ratio Y/Z Easy-peezy, eh? and it's only about 30 words long, leaving Amelia plenty of space to discuss other methods.

She should have discussed other methods, too, since this one wouldn't work for diddly in a forest or when there are other trees "downlight" of the subject tree. It also wouldn't work on a cloudy day. You could, however, use a clinometer or some simple trigonometric calculations to measure a tree (or any vertical height) under any conditions. But such solutions are apparently too hard for Allonsy...

Math's "too hard" – and that's just one of the reasons we hand out the Dumbass of the Day award to people like Amelia: for contributing to the stupidification of the internet.

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was homeguides.sfgate.com/judge-height-tree-68755.html

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