why aren't degrees a proper unit?
Nice puzzle but the use of unitless "x" for "x unit lengths" and for "x degrees" (not radians) is causing me nervous eyelid spasms. Technically it's not wrong I guess (bc degrees aren't a proper unit) but it's definitely not right either.https://twitter.com/_WTProject/status/1172916785764585473 …
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Well.. it's a unit of measurement of course, but it measures a dimensionless quantity. In my mind it's not a proper unit if you can't use it in dimensional analysis. It's as much a unit as "a dozen" is a unit.
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what's the problem with not using units? Everything can be normalised to rads so really, so long as all the units are the same, it doesn't matter. Just like all logarithms can be normalised to the nat. log., so it doesn't matter what base you actually use x-P
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I wouldn't have a problem if the angle would be x rad. But the angle is x degrees. So they omit a factor of pi/180 (or tau/360 if you prefer that).
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It’s pretty stupid because just trying the obvious as drawn example of both angles on the left being 90° (they have to add to 180°) gives a 54,72,90 right angle triangle on the right. There are no other solutions because if angle x gets smaller length x grows and vv.
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Yes, the way it's drawn is stupid. A much better way would have been to use different labels for the angle and the side (say alpha and x) and draw two pictures for two different values of alpha and x, none being the solution, and then asking for the alpha = x solution.
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when the bottom left angle is not a right angle, it has infintely many solutions for the length of side x. When botton left IS a right angle, x has length 90
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The way I understand it the top and bottom line are parallel. Thus the sum of both left inner angles is 180 degrees.
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Degrees aren't a unit but they are a unitless factor of π/180 so it's wrong.
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We're also required to assume the author is implying a non-self intersecting right quadrilateral. And there are an infinite number of answers.
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