Question

For each triangle shown below, determine whether you would use the Law of Sines or Law of Cosines to find angle x. Then find angle x to the nearest tenth.
A. 8.8 by The Law of Sines (SSA)
B. 22.9 by The Law of Cosines (SAS)
C. 10.7 by The Law of Sines (SAS)
D. 68.3 by The Law of Cosines (SSS)

Answer 1

know about sine and cosine laws ?

Answer 2

nope

Answer 3

and we would be doing 2 equations here right ?

Answer 4

because we have 2 angles that are given ?

Answer 5

http://en.wikipedia.org/wiki/Law_of_sines
http://en.wikipedia.org/wiki/Law_of_cosines

Answer 6

if you see sine law,
we can use it if we have 2 angles and 2 sides (with one unknown).

if you see cosine law,
we can use it if we have all 3 sides and 1 angle (with one unknown).

Answer 7

whats the case here ?

Answer 8

sin law

Answer 9

correct!

Answer 10

okay so .... ?

Answer 11

lets use it!
\(\large \dfrac{\sin A }{a} =\dfrac{\sin B}{b}\)

Answer 12

here A = 65
B=21
a =27
b=x

Answer 13

i thought it was the opposite like a/sin a = b/sin b

Answer 14

doesn;t make any difference :)

Answer 15

ohhhh ok well with that being said ... .906/27 = .358/x

Answer 16

and whats the value of x from there ?

Answer 17

x=10.669

Answer 18

thats correct! :)

Answer 19

so C is the answer

Answer 20

yes :)

Answer 21

thanks !

Answer 22

welcome ^_^