Question

Pre Calculus HELP!!

Answer 1

Where is the question....lol

Answer 2

In the triangle shown, what are the measurements of angles A, B, and C? Round your answers to the nearest 10th of a degree.

Answer 3

A, B, C are the angles!

Answer 4

*angels

Answer 5

Lower case a, b, c are opposite from their Capital letter.
a is opposite from A so the side for Angel A would be a = 6
b is opposite from B so the side for Angel B would be a =11
c is opposite from C so the side for Angel C would c = 7

Answer 6

Do you get it? Or do you need extra help? I don't mind giving you examples lol :) Good practice/ refreshing for me XD

Answer 7

Well I know that you need to set up three equations
cos(a)=(b^2+c^2-a^2)/2bc (you do this for the b and c equations as well)
then once you plug in the numbers, You have to take the inverse cos of the answer and then turn it into degrees.

Answer 8

Yes!!! Correct :)

Answer 9

Wait inverse cosine? That's based on...oh nvm! I getchu, lol took a while for me XD!

Answer 10

alright so for A, I got 29.79
because
Cos(A)=(11^2+7^2-6^2)/2(11)(7)
which is approximately 0.87
so cos^-1(0.87)=.52 radians
then .52(180/pi)=29.79

Answer 11

I would like agree with you.

Answer 12

Okay and cos(b)=64.74
because cos(b)=(6^2+7^2-11^2)/(2(6)(7))
which is approximately 0.43
cos^-1(0.43)-1.13
1.13(180/pi)=64.74

Answer 13

@Serenity74 do you not remeber how to do this? I am kinda stuck because I got the answer for C, but when A, B, and, C add up they dont equal 180. and all triangles are 180 degrees so I am confused now.

Answer 14

Do you mind if I asked what you got for C? :)

Answer 15

I'll assume *since I see the mistake already* That you received 35.10 roughly for C correct?

Answer 16

Aww, must be away from the computer momentarily

Regardless, your mistake lies with the calculation of B

In the sense that \(\large cos(B) = \frac{6^2 + 7^2 - 11^2}{2(6)(7)}\) will DEFINITELY come out to a negative result :)

*You just missed the negative sign..the result from that is -0.43 and the arccos of that is 115.37

Answer 17

I am back!

Answer 18

oh I see and now that we have B, 180-(A+C)=B

Answer 19

Well yeah exactly, you can use that to check :)

Answer 20

Sorrryyyy busy figuring out my physics project which I finally figured out and about to get egged and egg peeps lol. But yeah what @johnweldon1993 said is right. I got distracted sorry!!!

Answer 21

Okay well without using the check method, I went ahead and solved cos(c). Which was 34.95. It almost adds up but we have an point something so I think I may have calculated wrong

Answer 22

C should be 34.47

Answer 23

hmm I am a little lost in the calulculations because everytime I try to do cos(c) I am getting 34.95 but according to the check it should be 34.47

Answer 24

@johnweldon1993