Question

Find the measure of angle Y and the length of side y. Attatched picture below

Answer 1

I'm assuming you're doing trig?

Answer 2

yeah

Answer 3

ok, do you know what the \(\angle Y \) is?

Answer 4

did you look at the picture? that's all the info they gave me

Answer 5

yes

Answer 6

so, can you tell what "Y" is? :)

Answer 7

To find the angle you use the sides right?

Answer 8

oh wait, nevermind
Im stupid

Answer 9

tis ok :)

Answer 10

36

Answer 11

usually, yes, but is in this is simpler than that :)

Answer 12

It is?

Answer 13

well, how many degrees does the INTERNAL ANGLES of a TRIANGLE amount to?

Answer 14

180

Answer 15

right, and you are already given 2 angles off 3, so :)

Answer 16

but don't you just minus 144 from 180? and thats 36...

Answer 17

yes, thus \(\angle Y\ is\ 36^o\)

Answer 18

so what about side Y

Answer 19

now that you have the angle Y, you want to know its FACING OFF side, "y", with only using the adjacent legs/sides, which you're given.

for that just plug the values in the LAW OF COSINE formula

http://www.mathwarehouse.com/trigonometry/images/law-of-cosines/law-of-cosines-formula-and-picture2.gif

Answer 20

and you get "y" :)

Answer 21

So you would do 24 and 26, how do I plug that in...which formula again?

Answer 22

see the picture above? :), well, the link to the picture

or check your textbook, it'd be there, the LAW OF COSINES formula

Answer 23

Don't have a textbook, online school....ah.

Answer 24

So use the B formula?

Answer 25

well, you may want to get a good "cheatsheet" for trig, many online :)

Answer 26

wait, but this is only a Law of Sines quiz. Not cosine

Answer 27

right, the "B" in this case, just bear in mind that, each angle in a triangle, is always being FACED OFF by a side, and it always has 2 sides COMING OUT from it, so, the formulas use that, whatever angle is facing off whatever side, with whatever adjacent 2 sides

Answer 28

So in this case the angle is 36, and the two adjacent sides are 24 and 26

Answer 29

yes

Answer 30

So, ah, sorry I'm confused.. How do I even plug it in to the formula?

Answer 31

one sec

Answer 32

okay

Answer 33

$$\large
y=\color{blue}{24}^2+\color{red}{26}^2-2(\color{blue}{24}\times\color{red}{26})cos(36^0)
$$

Answer 34

THANK you, so much

Answer 35

ahemm, one quick correction

Answer 36

Oh, poo. I got a huge number not correct

Answer 37

$$
y^2=\color{blue}{24}^2+\color{red}{26}^2-2(\color{blue}{24}\times\color{red}{26})cos(36^0)\\
y=\sqrt{\color{blue}{24}^2+\color{red}{26}^2-2(\color{blue}{24}\times\color{red}{26})cos(36^0)}
$$

Answer 38

37.6?

Answer 39

is your calculator turned on in DEGREES mode? rather than in RADIANS mode

Answer 40

becuase in this case you're using 36 degrees, not 36 radians

Answer 41

15.6?

Answer 42

Yeah it was in radians

Answer 43

yes, that's what I got

Answer 44

Thank you so much, I have more questions if you're willing to help. Trig is hard to retain...

Answer 45

sure, just post them in the channel, and many of us can take a peek, and answer, and yes, if I see it, I'll help

Answer 46

alright