So we're going over the Holt Geometry. This is page 3 81 so if anybody at home. Is watching them we can and know what. We're doing all right so it says in. Center so we already started drawing. How do we find the in-center would we do. To this Holt Geometry we bisected the angles. Doing so i bisected all three angles and. They intersected at that point now this. Green line right here what is that green.

Line do that's the distance this Holt Geometry. Property about the in-center is that the. Distance from the in-center to the sides. Right from the point of intersection to. The sides all the same so that's what we. Were doing but it has to be what. Perpendicular doesn't it because that's. The distance from a point to a line has. To be a perpendicular distance so that. All has to be now if you look in the. Book they don't extend that all the way. They just stop right here at the.

## Holt Geometry Introduction

In-center just kind of cleans up a. Little bit doesn't know that stops right. At the in-center and this one stops. Right at the in-center ok so that's what. It looks like in the book looks a little. Cleaner doesn't it yes it does streaming. Okay yeah alright so what do we got Holt Geometry. Got some numbers here this is 20 before. This is 28 degrees this angle right. This one's 30 degrees and 11 is this. Yeah and that's what some letters in.

Here this is a app and see this is G B. And this is d all right we're good to go. They get everything other incentives Holt Geometry. Alright so what are we trying to do. First find the H so we're trying to find. This one right here this D H now what do. We know let's first take a look at th. Before you actually try to find the age. Let's see if there's any relationships. Between dhn anything else is there. Yeah what is it all the green ones are. All the same aren't they say that.

- Distance from the in-center to the Holt Geometry. Are going to be all the same so if i. Find eh is going to be the same thing as. GH nfh agree but the information given. I really don't have enough information. To find eh directly so what I'm gonna do. I'm gonna try to find one of the other. Green sides and can i find one of the. Other green sides fhi can find fh and. How did i know i can find fh because of. These sides are given this is 24. This is 25 and I don't know this alright.
- Let's just call it just must use Holt Geometry. Let's just call it access all right so i. Gotta find this one once i find fh d h. Is going to be the same exact thing we. Agree so how in the world do i find fh. Well first of all I've got a right. Triangle don't I and I know two sides of. A right triangle so we do that green. Theorem a common mistake in here I saw. When you guys are working on it on the. Study guide and on this thing and in the. Other class as well so you're not the. Only ones a lot of people just look at.
- The Holt Geometry and they automatically. Go 24 square plus 25 squared is that. What you do for connecting theorem. No not necessarily so remember that. Gurion theorem is a squared plus B. Squared equals C squared that's right. That's super-important right there c is. The hypotenuse which one is the. Hypotenuse in this triangle the 25 so it. Ok these are the two legs right these. Two things right here those are the two. Legs that are being added up what are.
- The two legs on this particular triangle. X + 24 right and so that i'm going to. Set it up so a lot of guys did. Pythagoras theorem but you didn't set it. Upright you put 24 square plus 25. Squared equals x squared but you've got. To make sure that you put the high. Pot news by itself everybody with me on. That and that comes out to several. Doesn't let you do the math this is. Actually a special triangle we're gonna. Have a chapter and I forget exactly. Which chapter it is this chapter 8 i'm.

Not really sure where we have Holt Geometry. Triangles that we talked about. Three-fourths 5 triangle in the past we. Haven't well we'll talk about that later. But you're actually going to memorize. Some of these special triangles and this. Is actually a triangle that you can. Actually memorized so instead of going. Through all the math you can look at it. And say something 24-25 of 7 24 25 right. And if you work it out they call it a. Pythagorean triple which means all three.

## Review Holt Geometry in 2017

Numbers a nice hole mother's day doesn't. Always come out a nice whole numbers Holt Geometry. On Pythagorean triples it does alright. So X is 7 so that means fh is 7 so what. Does that mean about D H has to be seven. As well now they don't ask you but what. If they ask you for GH that would be. Ok alright with me alright so DHS seven. That's our first question the next one. Well again I've got a right triangle.

Here don't night and look I know two. Sides of my right triangle again denied. I know this is 11 because they told it. To me and I know this one because i just. Found it right and so in order to do. This problem we're going to have to be. Able to do the problem for it and get. That right so this is seven this is 11. And you could actually software and tell. You the truth in that chapter where we. Talk about right triangles even if buy. It even if I'm i didn't know this.

We're going to learn something later on. You don't know it now but later on we're. Going to learn something where if you. Know this is 30 degrees and you know. This is 11 which they gave to you you. Could actually find DB on your own. Okay you're probably wondering how can i. Do that with just knowing an angle and. Decide well you'll have to wait. Alright sorry to get you all excited. About it fits great but right now since. I know this is 7i can do with a growing.

## How to buy Holt Geometry?

Theorems am I gonna set this Holt Geometry. Call this Y so i would do what. Yeah let's use the letters and numbers i. Have here so i get y squared plus wet 7. Squared equals y 11 squared I don't. Think this comes out as pretty does it. Now so so y squared equals of that 121. Subtract that which is 49 right and then. I don't know whatever that stuff is all. Right let's use the let's use the. Calculator and what we got 120 1-49. That's that and we'll have to do with. That take the square root of it so take.

The square root of my answer and then. 8.48 way around it so what is it. 8.5 so it's not exactly 8.5 but it's. Close enough so that's what DB is that's. One of our other answers now people 8.49. Or something because it doesn't say to. Yes so if you put 8.49 that's fine. Alright that'll work I've been fine with. That I'm not really that picking unless. They ask you to round it to a certain. Place right because that's part of the. Instruction so you have to round it but.

- The Holt Geometry on this one. Do not say that you had to round it to a. Certain place so don't worry so much. About the rounding alright let's do the. HJC let's go different color analysis. And blue for our angles h was eight. Right there H a/c so it's this angle. Right here that's what we're trying to. Find how in the world am I going to do. Well what do I know about this whole. Entire big triangle whole big white.
- Triangle right there what do I know Holt Geometry. About all three of these angles they add. Up to 180 don't think I can i find the. Other two big angles i know this is 28. What about this angle right here why is. This is the in-center how'd you get the. In-center you bisect the angle didn't. So this is 28 what's this alright with. That same reasoning that same thought. Process what else could you say the 30. Right this 30 and this 30 are the same. Aren't they will be bisected that angle.
- Is that going to help you. Well it's gonna help you find that whole. Big angle right there isn't it. So let's do that what's 30 or what this. Would be 60 right and this would be what. 56 have to do it right here plus 56 and. What's that hundred sixteen i do that. Ok so that's a hundred sixteen how do i. Find the big angle a that's right so go. 180 minus 1 16 and that's a 4 and that's. A six right so that big angle right. There 64 degrees but that's not what.
- They asked for this little angle HJC so. How do you do that just / to that's. Right so that angle right there would be. Makes sense right and that helped. Knowing that to find the in-center he. Had to bisect the angle did because we. Didn't know that you can be sunk you. Might have guessed but it's nice to them. Alright and dhgn6 find that was DD h g. So I'm trying to find this angle right. Hmm well let's take a look at this look. We have here I've got Holt Geometry.

Tonight now you might be able to look at Holt Geometry. It and just make an assumption but I. Don't like to work on assumptions okay. But look at these two triangles Sea this. Triangle here in this triangle right. Here they are what to each other they're. Congruent to each other articles look. I've got an angle an angle and decide. Then I got a 30 90 in this 11 I got a 30. 90 and this 11 so those triangles are. Congruent to each other so what is true. About this little angle right here and.

This little angle right here. They're both exactly the same aren't. They so what we're going to do we're. Going to go opposite of this we're going. To find the little angle first and then. We're going to double it instead of. Finding the big one and taking half of. To find the little one and then we're. Gonna double it makes sense alright so. Let's do that and that's kinda easy i. Got a 30 and 90 what's this going to be. This little angle is going to be 60. Isn't it which means this angle is 60.

And what's the whole big angle a hundred. And twenty ok so that would be a hundred. And twenty degrees a nice innit see how. That congruent triangles stuff helps you. Out a little bit and you might have. Looked at it and just guessed and might. Have just made an assumption that on. Yeah they look equal to each other but. You don't want to do that you want to. Know exactly why they're equal to each. How's that alright good so that's in.

Center was there one with a Centurion. This there wasn't the first one okay. Oh yeah they did like two through four. Are you okay with the century thing how. Do you find the century was the median. What is the meeting you go from a vertex. Where to the to the midpoint of the. Opposite side okay and remember the. Centuries that one where the one side is. Double the right the longer side is. Double the shorter side and all that. Kind of stuff i wish i could i I want to.

Think of ways to memorize remember these. All the time and I can't think of a Holt Geometry. Google it I'm don't know every time i've. I've seen several videos of people. Teaching this stuff and they don't have. Like a nice pretty way to remember they. Say this is the incenter this is what it. Does this is the century this is what it. Does and they don't have like a little. Cutesy way the remember you know I mean. Like my dear Aunt Sally you know that.

Please excuse i saw on facebook. Yesterday or something that somebody. Posted i don't know some website or. Something had like a t-shirt and I had. Some lady's name on it and it had some. Lady's face on it and it said please. Excuse my dear Aunt Sally or something. Like that and I guess it's for Kiki math. Like me in this box she would love that. Is every ok that's ok that's fine. Is there anything else we good with the. Other stuff the range between those two.

Numbers that's easy. Yeah my goodness this should be a Holt Geometry. You think I hope so what's difficult. This was difficult was it goes so hard. Wasn't what about the thing that's. Greater than when they give you the two. Triangles and you know the two angle you. Look opposite the bigger angle that's a. Everybody ok with that part sure I just. Want to make sure that we cover all the. Bases and you don't just sit there quiet. And don't ask me a question right the.

Only proof there's only one proven and. Indirect proof minutes and we kind of. Talked about that earlier now should be. Pretty easy i think thing that scares me. Is that I looked on the computer and I. Had chapter five test and then I had a. Chapter 5 like what i call it i had like. A second test we call like a not a. Practice test like a redo test I didn't. Call it that it call it something but. I'm thinking all I must have made that. Because they did bad the first time and. Then i had to give him another one like.

A retake that's why I called a retake. I don't think we're going to need to. Retake I think you guys have to find the. First time hopefully any other questions. I think there's like two of the things. Yeah okay what I thought we would do. Let's go question by question on what's. Going to be what type of problems gonna. Be on the test okay so that you have no. Doubts whatsoever what to study. Ok so one two three it's basically what.

We just did that in center thing and. I'll even tell you it's all about the. In-center we have to find a missing. Angle missing sides and all that kind of. Alright i am recording this alright four. And five is circumcenter same kind of. Deal i'll give you a triangle I tell you. That is the circumcenter and then I ask. A couple questions you know find the. Length of this and all that kind of. Alright how do we find the circumcenter. You remember that perpendicular bisector. So for circumcenter two perpendicular. Bisector and what's true about that it's. Equidistant from vertices ok we talked. About that quite a bit yesterday was one. Of that was one of those problems I. Forget I'm trying to remember what. Problem we're talking about that anyway. So circumcenter you can look that up. K 6 through 8 is century and they're all. Very similar to each other whether give. Hey it's all drawn out for you you don't. Have to draw it and find it it's all.

Drawn out for you and it says this is Holt Geometry. The end center this is the circumcenter. This is the centroid they're going to. Give you some numbers give you some. Angles and they're going to ask you to. Solve for certain things yes you will. Not know you won't have to do any graph. Actually I just lied to you I didn't lie. Number nine is one of those ok where. I'll give you three ordered pairs which.

Makes a triangle obviously and you have. To tell I'm not gonna tell you which one. But you're going to have to either find. The in-center the circumcenter or the. Centroid ok so you will have to graph it. I'll give you a little graph on your. Answer sheet again low X&Y axis thing. We're going to little boxes and all that. You know what I mean we'll graph paper. Thing and so you just find one of those. I'll say here are the ordered pairs find. The in-center or find the circumcenter. Ok the centroid is what what do you do. You gotta look at that chart remember. What that chart is where that chart is. Ok so how do you find the century find. The way the median ok how do you find. That's the one that we did now. Oh that's right how sorry I thousand. Thinking of the maximum this is. Perpendicular bisector k so this is. Median this is perpendicular bisector. And this one is angle bisector ok you.

Got find which one yeah where is the. I'm not sure what you're asking already. Told you what these are all about. Ok this one right here they give you. Three ordered pairs and they're going to. Say tell me the ordered pair or tell me. The what they say the coordinate of the. In-center or tell me the coordinates of. The circumcenter or tell me the. Coordinates of the century and so your. Answer is going to be an ordered pair. Okay now no catania that that's all that. Stuff I just told you you keep asking.

The same question i'm not sure what. You just have to find where the ordered. Pair is now I explained this already. They give you everything they give you. The picture go back and listen I've said. This before and I'll say it again they. Give you the picture and they draw the. In center and they draw the circumcenter. And they draw the centroid alright just. Like this just like this they draw this. And they give you some stuff and they.

Ask you some questions okay what is Holt Geometry. Now I said for all of these for the. In-center circumcenter century they're. All very very similar to each other. Ok alright let's keep going 10 and 11 is. Where they give you the triangle and. They say with the angles and sides from. The smallest to largest so from the. Smallest you've done a lot of those know. Ok so that's 10 11 12 and 13 is where. You state the assumption so that's easy. See there's two of those to an indirect.

Proof right and that's all it says just. State the assumption you don't have to. Do a whole indirect proof on it just. Read the instructions and it will say. State the assumption number 14 is your. Indirect proof that your only one. It's very simple basic one it's nothing. Real complicated we already went over. One today earlier so it's going to be. It's going to be is it possible to form. A triangle is it possible to form a.

Triangle with those lengths so I give. You three lengths and you tell me if you. Can make a triangle you take the Holt Geometry. Smaller ones that it's gotta be bigger. Ok so there's two of those alright 17 is. Find the range of possible sides lengths. For the third side I'll just yes we just. Subtract them you Adam you put less than. Ok that's that one find the range. Ok then 18 through 20 it's the triangle. Inequality ones i'll just write that. Triangle inequality right that's where.

They tell you one side is bigger than. The other side right and then so what. You do you look opposite so that Holt Geometry. Opposite the bigger side is bigger than. The angle opposite the smaller side. Remember that so we'll say compare. Triangle ABC or angle ABC to triangle or. Two angle whatever d e f yeah whatever. Ok and then you gotta comparing so what. Do you say you say well it's either last. Dance greater than c4 and that's 18. Through 20 that's your test should be.

Holt Geometry easy shouldn't right we've. Covered all this stuff i mean this is. The hardest part so make sure you go. Through make sure you remember how do. You find the in-center how do you find. The circumcenter how do you find the. Centroid and what is the what's the. Special relationship you know at that. Point what is the in-center do well it's. Equidistant from what what's the. Circumcenter it's equidistant from what. It's a century right the longer one. Twice as big as a shorter why not longer.