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Mathematics 9 Online
nikkixmarie:

does anyone know how to solve special right triangles?

nikkixmarie:

1 attachment
SelfishQueen:

Did you already get help?

nikkixmarie:

no i didnt

nevaehhh:

Okay I can help-

nikkixmarie:

i just need an explanation on how to do it, thank you!

nevaehhh:

Okie dokie... so do you know the Pythagorean Theorem ?

nikkixmarie:

um just a little not alot

nevaehhh:

Well the Pythagorean Theorem is a^2+b^2=c^2.

nevaehhh:

Do you know what a hypotenuse is ?

nikkixmarie:

yes i do

nevaehhh:

Ok, well the c^2 part is the hypotenuse in the equation. Lemme draw you something rq.

nikkixmarie:

okay

nevaehhh:

|dw:1610994606613:dw|

nevaehhh:

so... that big side is the c^2.

nikkixmarie:

ok got it

nikkixmarie:

how would you go about finding the missing sides of the triangle?

nevaehhh:

Ok, well I just went on a whole different route... Ignore all that. Ok here's what you really need to know. Lemme draw another thing rq.

nevaehhh:

|dw:1610994843730:dw|

nevaehhh:

this is the equation we're going to start with.

nikkixmarie:

okay

nevaehhh:

Ok to start off... we need to identify all the angles of the triangle.

nevaehhh:

Can you tell me what the angles are?

nikkixmarie:

45,45,90

nevaehhh:

Okay... well there is different rules for (45.45.90) and (30,60,90) triangles.

nevaehhh:

In a 45,45,90... the legs (the other sides other than the hypotenuse) are found by dividing the hypotenuse by \[\sqrt{2}\]

nevaehhh:

To find the hypotenuse, you multiply the legs by \[\sqrt{2}\]

nevaehhh:

|dw:1610995249005:dw|

nevaehhh:

You find the "long side" by multiplying the side by the square root of 2.

nikkixmarie:

but where did the 1 come from

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie but where did the 1 come from \(\color{#0cbb34}{\text{End of Quote}}\) The 1 is the measure of the side, not the hypotenuse.

jhonyy9:

why are these triangles special right triangles ?

nevaehhh:

Don't think too hard... the 1 is just the measure of the side, that's all.

nikkixmarie:

oh okay

nevaehhh:

|dw:1610995533163:dw|

jhonyy9:

just use the law of sin or cos and solve them but you need to know the trigonometrical value of sin 45° or cos 45° and so much

nevaehhh:

|dw:1610995661772:dw|

nikkixmarie:

4?

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie 4? \(\color{#0cbb34}{\text{End of Quote}}\) Correct~

nevaehhh:

So now you have the answer to your first question.

nevaehhh:

Wait wait wait-

nevaehhh:

We still need to find B- but in a 45, 45, 90 triangle... the 2 sides are the same, EXCEPT for the hypotenuse.

nikkixmarie:

okay, these are so hard there is still 4 more after this ill try to figure them out

nevaehhh:

Do you want me to go slower ? What can I do to help ?

nikkixmarie:

no its fine its just confusing to me thats all

nevaehhh:

Ok... well we're gonna try the 2nd one, lemme draw it rq-

nevaehhh:

|dw:1610996001783:dw|

nevaehhh:

what are the angles in the triangle ?

nikkixmarie:

45,45,90

nevaehhh:

|dw:1610996114904:dw|

darkknight:

Special right triangles follow the form 45, 45, 90 or 30, 60, 90 These are angle measures and their corresponding side lengths are \[x, x, \sqrt{x}\] and \[x, x \sqrt(3), 2x\] respectively

darkknight:

For example if you are given a 45-45-90 triangle, and they say the length of a side opposite one of the 45 degree angles is 5, the side opposite the other 45 degree angle is also 5 and the hypotenuse is \[5\sqrt{2}\]

nikkixmarie:

the legs are missing btw

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie the legs are missing btw \(\color{#0cbb34}{\text{End of Quote}}\) Ok remember how I said that the legs are equal in a 45, 45, 90 ? Well, that means x and y are equal, so let's solve for the legs...

darkknight:

in that case other way around. If you know hypotenuse in a 45-45-90 triangle the legs are equal to the hypotenuse divided by sqrt(2)

nikkixmarie:

so when you divide the hypotenuse by that you are given the legs?

nevaehhh:

|dw:1610996401835:dw|

jhonyy9:

so my opinion that all what you need to know - the law of sin and cos and that sin45° = cos45° = \[\frac{ \sqrt{2} }{ 2 }\]

darkknight:

for a 45-45-90 degree yes @nevaehhh

darkknight:

correct @jhonyy9 think about how the 45-45-90 is defined on a unit circle. You take the sin(45) which is the opposite/hypo|dw:1610996612703:dw| then sin(45) = x/1 so x = sin(45) = sqrt(2)/2

nevaehhh:

if yall could let me have this one- you see im only 47👉🏼👈🏼

darkknight:

thats the case for the hypo being 1 if the side was 1 then we divide the hypo by sqrt(2)/2 or multiply by 2/(sqrt(2)) to get us the value

darkknight:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @darkknight Special right triangles follow the form 45, 45, 90 or 30, 60, 90 These are angle measures and their corresponding side lengths are \[x, x, \sqrt{x}\] and \[x, x \sqrt(3), 2x\] respectively \(\color{#0cbb34}{\text{End of Quote}}\) which is where this comes in

nikkixmarie:

I feel bad for not understanding still, im confused again

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie I feel bad for not understanding still, im confused again \(\color{#0cbb34}{\text{End of Quote}}\) what are you confused about ?

darkknight:

@nevaehhh feel free to help out. \(\color{#0cbb34}{\text{Originally Posted by}}\) darkknight \(\color{#0cbb34}{\text{Originally Posted by}}\) @darkknight Special right triangles follow the form 45, 45, 90 or 30, 60, 90 These are angle measures and their corresponding side lengths are \[x, x, \sqrt{x}\] and \[x, x \sqrt(3), 2x\] respectively \(\color{#0cbb34}{\text{End of Quote}}\) which is where this comes in \(\color{#0cbb34}{\text{End of Quote}}\) use this for it

nevaehhh:

Just solve the equation I gave you... look at the drawing rq.

nevaehhh:

|dw:1610996906591:dw|

nikkixmarie:

is it 2

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie is it 2 \(\color{#0cbb34}{\text{End of Quote}}\) Around 2.83 to be exact

nevaehhh:

But... what does this mean ? What do x and y equal ?

nikkixmarie:

the 2.83

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie the 2.83 \(\color{#0cbb34}{\text{End of Quote}}\) good job- x=2.83 and y=2.83

nevaehhh:

Do you want me to do the next question with you ?

nikkixmarie:

can i try to solve it then you tell me if its right?

nevaehhh:

Absolutely.

nikkixmarie:

yea i need help with this one the hypotenuse is confusing

nikkixmarie:

i mean the leg sorry

nevaehhh:

You were right the first time, we're solving for the hypotenuse-

nikkixmarie:

wait what do you multiply again the find the hypotenuse.

nikkixmarie:

to*

nevaehhh:

|dw:1610997295994:dw|

nevaehhh:

|dw:1610997415055:dw|

nikkixmarie:

so 3?

nevaehhh:

Yep- that's right

nikkixmarie:

3 would be the hypotenuse and the other equation would be the leg

nevaehhh:

Yep- the other leg would equal the other one lmao-

nikkixmarie:

ohhhhhh

nevaehhh:

But the hypotenuse is 3.

nikkixmarie:

ok i got it noww

nevaehhh:

Okie dokie~ hope i helped lmao

nikkixmarie:

you did so much thank you!

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie you did so much thank you! \(\color{#0cbb34}{\text{End of Quote}}\) you're welcome :)

nikkixmarie:

u need to be promoted girl

nevaehhh:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @nikkixmarie u need to be promoted girl \(\color{#0cbb34}{\text{End of Quote}}\) PREACHHH- i really do smh😭

nikkixmarie:

yessss fr omg

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