# What is a Hypotenuse (Quick, off the Top of Your Head)? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [August 9, 2013, 5:06am UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782 "2013-08-09T05:06:50Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [August 9, 2013, 7:21pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/41 "2013-08-09T19:21:40Z")
> [@Inner\_Stickler](#): > > I also remember what SOHCAHTOA stands for… Isn’t that what happened to the Roanoak colony? ---
**Author:** ![Inner\_Stickler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inner_stickler/32/318_2.png) [@Inner\_Stickler](https://boards.straightdope.com/u/Inner_Stickler)\ **Post date:** [August 9, 2013, 7:35pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/42 "2013-08-09T19:35:51Z")
Yes, they were abducted by a marauding band of Flatlanders who carved their callingcard, a trigonometric mnemonic on a tree. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [August 9, 2013, 7:47pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/43 "2013-08-09T19:47:03Z")
> [@Derleth](#): > > The side opposite the right angle in a right triangle. > > Equivalently, any diagonal joining two opposite corners of a rectangle or square. Pssst…a square _is_ a rectangle, this being SDMB and all. Yeah, I know, you know, but the USPS doesn’t. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [August 9, 2013, 8:06pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/44 "2013-08-09T20:06:23Z")
an uncle who doesn’t have a strong accent. ---
**Author:** ![BrotherCadfael](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)\ **Post date:** [August 9, 2013, 8:13pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/45 "2013-08-09T20:13:34Z")
According to my dad, the hypotenuse is the upstairs bathroom when it is occupied. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [August 9, 2013, 8:41pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/46 "2013-08-09T20:41:01Z")
> [@panache45](#): > > Oh, and by the way, the scarecrow got it wrong. I remember re-watching that movie when I was in my 20s and realizing that he was wrong. I was inordinately proud of myself. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [August 9, 2013, 8:42pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/47 "2013-08-09T20:42:53Z")
> [@BrotherCadfael](#): > > According to my dad, the hypotenuse is the upstairs bathroom when it is occupied. 😃 ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [August 9, 2013, 9:46pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/48 "2013-08-09T21:46:25Z")
> [@Chefguy](#): > > I remember re-watching that movie when I was in my 20s and realizing that he was wrong. I was inordinately proud of myself. You know, I just always thought that was a [Simpsons thing](http://www.youtube.com/watch?v=fO1Vhc88QkM). I didn’t realize the line comes from _The Wizard of Oz_. Then again, I don’t think I’ve seen the _Wizard of Oz_ in its entirety since _The Simpsons_ began. ---
**Author:** ![Dr.Girlfriend](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.girlfriend/32/193_2.png) [@Dr.Girlfriend](https://boards.straightdope.com/u/Dr.Girlfriend)\ **Post date:** [August 9, 2013, 10:00pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/49 "2013-08-09T22:00:26Z")
> [@BrotherCadfael](#): > > According to my dad, the hypotenuse is the upstairs bathroom when it is occupied. Ok, I had to read that twice, but then I seriously LOL’d. 😃 I knew off the top of my head that a hypotenuse was part of a triangle but I couldn’t get more specific than that until I read the whole thread. I’ve long since forgotten any geometry I managed to absorb in high school. I have to take a couple math courses next term in school and I’m more than a little nervous… ---
**Author:** ![want2befree](https://avatars.discourse-cdn.com/v4/letter/w/3e96dc/32.png) [@want2befree](https://boards.straightdope.com/u/want2befree)\ **Post date:** [August 9, 2013, 10:05pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/50 "2013-08-09T22:05:45Z")
I’m so embarrassed, I was thinking hypotenuse might be a grammatical term! :smack: ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [August 9, 2013, 10:15pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/51 "2013-08-09T22:15:26Z")
Doctor Who answer: If the square of the hypotenuse is equal to the sum of the squares of the other two sides, why is a mouse when it spins? Harry Sullivan is an idiot! ---
**Author:** ![Skald\_the\_Rhymer](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Skald\_the\_Rhymer](https://boards.straightdope.com/u/Skald_the_Rhymer)\ **Post date:** [August 9, 2013, 10:26pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/52 "2013-08-09T22:26:11Z")
A hypotenuse is the longest side of a right triangle, which is, if I recall, necessarily the side opposite the 90 degree angle. ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [August 9, 2013, 11:45pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/53 "2013-08-09T23:45:30Z")
> [@pulykamell](#): > > Of course, a “straight angle” is 180 degrees, while a right angle is 90 degrees, so I’m not entirely sure why a 90 degree angle would take the Latin root for “straight.” I believe because if a right triangle lays on one leg, the other leg will be standing straight up. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [August 10, 2013, 12:53am UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/54 "2013-08-10T00:53:19Z")
> [@](#): > > What is a Hypotenuse (Quick, off the Top of Your Head)? Oh, everyone knows that. Roman central heating ---
**Author:** ![Becky2844](https://avatars.discourse-cdn.com/v4/letter/b/91b2a8/32.png) [@Becky2844](https://boards.straightdope.com/u/Becky2844)\ **Post date:** [August 10, 2013, 1:52am UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/55 "2013-08-10T01:52:51Z")
A triangle with the top flattened obscurely. Or that’s the theory. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [August 10, 2013, 8:20am UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/56 "2013-08-10T08:20:21Z")
> [@Giles](#): > > If the lengths of the three sides of the triangle are a, b and c, where c is the hypotenuse, then the radius is (a + b - c) / 2. Yes, and the three sides can be partitioned into two sections each, where each section is one of (a + b - c) / 2, (b + c - a) / 2, and (c + a - b) / 2, and each side has a different pair of sections [a = (a + b - c) / 2 + (c + a - b) / 2, etc]. This is true of all triangles, but in right-angled triangles only, the radii that meet the non-hypotenuse sides form a square with the (a + b - c) / 2 sections, from which it can be seen that they are themselves of that length. Anyway, a hypotenuse is a method of punishment for a worker in clay who takes drugs. > [@Skald\_the\_Rhymer](#): > > A hypotenuse is the longest side of a right triangle, which is, if I recall, necessarily the side opposite the 90 degree angle. Yes, and it must be, because in all triangles, the longest side is opposite the largest angle, and in a right triangle neither of the other angles can be larger than 90 degrees. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [August 10, 2013, 10:51am UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/57 "2013-08-10T10:51:26Z")
What is a Hypotenuse - It’s a greeting for someone named Potenuse ---
**Author:** ![Bozuit](https://avatars.discourse-cdn.com/v4/letter/b/edb3f5/32.png) [@Bozuit](https://boards.straightdope.com/u/Bozuit)\ **Post date:** [August 10, 2013, 11:29am UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/58 "2013-08-10T11:29:01Z")
Thesumofthesquarerootsofanytwosidesofanisocelestriangleisequaltothesquarerootoftheremainingside! ---
**Author:** ![Son\_of\_a\_Rich](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/son_of_a_rich/32/5439_2.png) [@Son\_of\_a\_Rich](https://boards.straightdope.com/u/Son_of_a_Rich)\ **Post date:** [August 10, 2013, 2:06pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/59 "2013-08-10T14:06:21Z")
> [@Bozuit](#): > > Thesumofthesquarerootsofanytwosidesofanisocelestriangleisequaltothesquarerootoftheremainingside! Best said while wearing Henry Kissinger’s glasses. ---
**Author:** ![That\_Don\_Guy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/that_don_guy/32/538_2.png) [@That\_Don\_Guy](https://boards.straightdope.com/u/That_Don_Guy)\ **Post date:** [August 10, 2013, 4:07pm UTC](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782/60 "2013-08-10T16:07:44Z")
> [@Inner\_Stickler](#): > > I also remember what SOHCAHTOA stands for and the law of sines. Yes, but what about the law of _cosines_ (which, surprisingly, has little to do with the law of sines)? In fact, the Pythagorean theorem is a special case of the law of cosines. I usually use the Pythagorean theorem as one of the things I list when I ask people who think “schools shouldn’t teach facts; they should teach you how to learn” (i.e. “don’t teach to the test”) what “facts” kids _should_ know when they leave school (along with things like “Where is the USA on a world map/globe?” and “Were the USA and USSR on the same side in World War II or not?”). [Previous page](https://boards.straightdope.com/t/what-is-a-hypotenuse-quick-off-the-top-of-your-head/665782.md?page=2)