Question

matttth

Answer 1

http://prntscr.com/ic76v5

Answer 2

choices
http://prntscr.com/ic76y9

Answer 3

@Sarah10 What do you think?

Answer 4

so at this point im confused am i supposed to make a proportional statement?

Answer 5

or do i use Pythagorean theorem to find the x ?

Answer 6

wait do i go like 25^2 and i choose one of the degrees in the choices to find which one gives me 180 ?

Answer 7

First off, by what means are these triangles similar?

Answer 8

is it SSS?

Answer 9

Yes

Answer 10

All the sides are similar by a common proportion of 3

Answer 11

So when you have three sides, and want to solve for an angle, what should you use?

Answer 12

Pythagorean theorem

Answer 13

am i wrong lol?

Answer 14

That formula is:

\[a^2 + b^2 = c^2\]

Whilst it does relate three sides, and does apply to right angles, it makes no reference to an angle. Thus we cannot use it, since it only talks about the legs and hypotenuse of a right triangle.

Answer 15

wait ill solve it and you tell me if im wrong

Answer 16

Okay

Answer 17

25+53=78
78-180= 102
102+53+25=180

therefore C is correct

Answer 18

i messed up didnt i XD

Answer 19

You're correct, but I don't know about that math...

I used the Law of Cosines. Have you heard of it?

Answer 20

i havent learned about it but i have a question regarding it
http://prntscr.com/ic7dkh

can you please help ?

Answer 21

are you supposed to learn about that in geometry or trig ?

Answer 22

Law of Cosines:

\[a^2 = b^2 + c^2 - (2bc) \cos A \]

Answer 23

It's trig

Answer 24

so how will i input that formula from this http://prntscr.com/ic7dkh

Answer 25

I was referring to the previous problem.

Answer 26

oh i see

Answer 27

I used Law of Cosines and got 53. When you did that adding of angles, that didn't make any sense.

Answer 28

lol i dont know but ive been doing it like that for a while

Answer 29

25 + 53 is 78. That's two angles. The third angle is 90 degrees. That's why it doesn't make sense. 78 + 90 = 168.

Answer 30

first i did was take the given degree
and add it to one of the choices
so
25 + 53= 78

after i got that i subtracted 78 from 180 (i always subtract it with 180)
after i get my result which is 102

then i see if they all add up to be 180

102+53+25=180

Answer 31

im in geom i haven't been taught about cos
i dont know why she is giving it to us ..

Answer 32

do you get how i was thinking lol

Answer 33

Yeah, I am sure you could do this some other way. But Law of Cosines is easy, and fast. Your method relies on the number you grab from multiple choice (if there is any) is the correct one. Even then, you are using angles from different triangles. Thus why you get 78 after adding two angles, even though 90 is the third angle for both. The number is off because you're using angles from different triangles.

Answer 34

Have you ever worked with sin, cos, or tan before?

Answer 35

no i have not i think i will be getting into it soon

Answer 36

oh i get the method i use will be at a disadvantage if i had no choices

Answer 37

thank you veryyy much !!

Answer 38

I may have time tomorrow to teach you Law of Sines/Cosines. It will make Geometry a breeze and the rules are easy to remember. If you're on around this time.

Answer 39

thank you very much