Pythagorus' Theorum - Math Lessons - sides - By tecmath
Transcript
| 00:0-1 | Good and welcome to the Tech Math channel . What | |
| 00:02 | we're gonna have a look at this video is going | |
| 00:03 | to be looking at how to find the shortest sides | |
| 00:06 | . Are these A or B sides ? When we're | |
| 00:09 | using Pythagoras ? Okay , so , uh , the | |
| 00:11 | Pythagorean theory and first off number one , we can | |
| 00:14 | use it to work out . Well , basically what | |
| 00:17 | was stating is that some of these two square of | |
| 00:21 | these two sides . Okay , so we square this | |
| 00:23 | side and we square this side . We add them | |
| 00:25 | together . Let's get away the same as the square | |
| 00:27 | on this side , which this side here is called | |
| 00:30 | the high pot . And so we have ice squared | |
| 00:33 | plus B squared is equal to c squared here . | |
| 00:37 | We're going to be working out how we can work | |
| 00:39 | out , say , one of these signs , these | |
| 00:42 | shorter sides , given that's two other sides . Okay | |
| 00:45 | , It's not too hard . Just requires first putting | |
| 00:48 | it into this formula here , and then moving things | |
| 00:51 | around . So let's launch straight into it . So | |
| 00:53 | , this is the type of example you're given , | |
| 00:55 | where you are asked to work out uh this unknown | |
| 00:59 | side here . Okay , what about to give it | |
| 01:01 | a bit of a letter value ? I'll call this | |
| 01:02 | one X . Okay . So what is that unknown | |
| 01:06 | side here ? Okay , so first off , I'm | |
| 01:09 | gonna jot down the pythagorean . The pythagorean , the | |
| 01:13 | pythagoras theorem , which is a squared plus B squared | |
| 01:19 | equals C squared . And let's just slide out things | |
| 01:23 | into the formula here . So we have it's called | |
| 01:27 | X here , X squared . Ok , so X | |
| 01:31 | . What am I doing there ? I didn't make | |
| 01:33 | a bit of equals their X squared plus B squared | |
| 01:37 | . Ok , so plus eight squared equals c squid | |
| 01:45 | . 10 square . Okay , we can work this | |
| 01:48 | out a little bit further down so we can keep | |
| 01:50 | our X squared . It was eight squared is 64 | |
| 01:56 | And this equals to 10 times 10 , which is | |
| 01:58 | 100 . Yeah . What you want realized with this | |
| 02:01 | is that we want to get X by itself here | |
| 02:04 | And that's really , really easy . The way we | |
| 02:06 | do this is as follows , We just take the | |
| 02:08 | 60 for both sides . If we take 64 Off | |
| 02:12 | this side , we also take 64 Off this side | |
| 02:15 | . So everything stays . No , I said equal | |
| 02:18 | . So we're going to end up taking 64 from | |
| 02:21 | 64 , which cancels each other out . So it | |
| 02:23 | is on this side we're gonna be stuck with or | |
| 02:25 | left with X squared 100 take away 64 . The | |
| 02:30 | answer is 36 . Okay , so X . He's | |
| 02:36 | going to be equal to the square . I don't | |
| 02:38 | know what happened there . X is going to be | |
| 02:42 | equal to the square root of 36 . And so | |
| 02:47 | therefore the square of the 36 . What ? Nobody | |
| 02:49 | at times by itself to get 36 , that's six | |
| 02:53 | . And we can put these units back therecm . | |
| 02:55 | This unknown side here is 6cm . You see how | |
| 02:59 | we do that ? That's fairly fairly simple . Okay | |
| 03:04 | , let's work out another example here to say this | |
| 03:08 | is the one we want to work out . It | |
| 03:10 | is the one we want to work out . Move | |
| 03:12 | just a little bit again . Let's just jot down | |
| 03:15 | the formula . So I squared . What's B squared | |
| 03:21 | equals ? See squid . Okay . And we'll give | |
| 03:26 | this one unknown side a letter . Let's this time | |
| 03:29 | let's call it X . Just for the heck of | |
| 03:31 | it . And we will say therefore X squared plus | |
| 03:36 | B squared , Which is four squared equals , I | |
| 03:42 | mean squared . Okay , we're going to end up | |
| 03:47 | running out of room in a second . On this | |
| 03:48 | side , that's a car can deal with this . | |
| 03:50 | We're going to end up with X squared plus , | |
| 03:56 | So four times 4 is 16 and then we have | |
| 04:01 | 18 square , so 18 times 18 . 324 . | |
| 04:11 | 300 24 . Okay . So what are we gonna | |
| 04:17 | do now with this ? Well , what we can | |
| 04:19 | do is we can get this X . Or by | |
| 04:22 | itself . And the way we'll do this is we're | |
| 04:24 | going to take 16 of both sides . I don't | |
| 04:29 | have to move this whole entire thing over here . | |
| 04:31 | I can see this now . Well , with the | |
| 04:34 | miracles of computers will be able to do this . | |
| 04:36 | You watch this for magic , Look at that . | |
| 04:40 | Okay , So I'll move the whole lot over there | |
| 04:41 | , but I'm not going to run out of space | |
| 04:44 | and let's get back to it . Um So We | |
| 04:49 | take 16 off this side . We're going to end | |
| 04:51 | up with X squared . I want to be too | |
| 04:55 | far X squared . And this is gonna be equal | |
| 04:59 | to where we were going to cancel each other out | |
| 05:00 | obviously . And We're then gonna take 16 off here | |
| 05:05 | . So you need this answer of 300 good . | |
| 05:13 | Okay . So X is going to equal the square | |
| 05:17 | root , The 308 , which will equal . Let's | |
| 05:23 | have a look . 308 in verse squared . He's | |
| 05:31 | 17.5 17.5 . We're using status . Okay , So | |
| 05:42 | how did you go with that ? Let's have a | |
| 05:45 | look at one more example to say we have this | |
| 05:48 | particular one here . Again , let's label this unknown | |
| 05:52 | side . And again , it's one of the shortest | |
| 05:54 | sides . Okay , So right out of formula I | |
| 05:59 | squared plus B squared equals C squared . Okay , | |
| 06:06 | let's substitute in some values here . So we're going | |
| 06:10 | to call this I think we're gonna call this one | |
| 06:12 | here , X against X squared plus B squared . | |
| 06:17 | What's B squared ? Well , this is the shorter | |
| 06:19 | side here , so 12 squared equals This one here | |
| 06:24 | squared 15 squid . Okay , so it's worth the | |
| 06:29 | zap X squared Plus 12 times 12 is 144 , | |
| 06:35 | 15 times 15 is 225 . Okay , so let's | |
| 06:41 | get this x squared all by itself . And when | |
| 06:44 | we do this is we take 144 for both sides | |
| 06:51 | . And when we do this , we end up | |
| 06:53 | with X squared Because these guys get rid of one | |
| 06:57 | another 225 take away 144 . This is equal to | |
| 07:05 | 81 , Which is really , really handy because 81 | |
| 07:10 | It's quite an easy number to work at the square | |
| 07:12 | root of yeah , because you'll see in a second | |
| 07:14 | uh X is equal to the square root of 81 | |
| 07:19 | And therefore squared of anyone . Want nobody at times | |
| 07:23 | by itself to get 81 Magical answer is nine . | |
| 07:28 | So how did you go with it ? Pretty good | |
| 07:30 | . nine . What ? nine cm . Put them | |
| 07:34 | here in a tent . Alright , so hopefully you're | |
| 07:36 | pretty good with these . Uh so what we're gonna | |
| 07:38 | have a look at networks , we're gonna start having | |
| 07:39 | a look at shops that don't necessarily have triangles in | |
| 07:42 | them . And how we can use . I think | |
| 07:44 | this is theorem to actually work these out . And | |
| 07:47 | I hope to see you that see you next time | |
| 07:49 | . Bye . |
Summarizer
DESCRIPTION:
OVERVIEW:
Pythagorus' Theorum - Math Lessons - sides is a free educational video by tecmath.
This page not only allows students and teachers view Pythagorus' Theorum - Math Lessons - sides videos but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.
GRADES:
STANDARDS:
