Top Posters
Since Sunday
5
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
New Topic  
twinzmomma twinzmomma
wrote...
Posts: 8
Rep: 0 0
10 years ago
Theres a Triangle Each tip has A, B, or C near it. One side has 25 the other 21. And in one corner inside the triangle theres a 37 degree.

   Find the measure of angles B and C using the law of sines. Round to the nearest hundredth.
Read 307 times
2 Replies
Replies
Answer accepted by topic starter
-Saint--Saint-
wrote...
10 years ago
Sign in or Sign up in seconds to unlock everything for free
1

Related Topics

wrote...
10 years ago
a / SinA = b/SinB = c/SinC

where
upper case letters = Angles,
lower case letters =  there opposite triangle 'side'

Depending on weather the 37 degrees is opposite to the 25 or the 21 will determine the answer, but ill do both
===========================================================
1)
===========================================================
call 'a' 25 therefore 'A' is 37'b' = 21
so 25 / sin37 = 21 / sinB = c / SinC
25 / sin37 = 21 / sinB
cross multiply

21Sin37 = 25SinB
21Sin37 / 25 = sinB
B = ArcSine((21Sin37)/25
B= **30.366**

3 internal angles of a tryangle = 180,
therefore C = 180-37-30.066
C=**112.934**

a/SinA = c/SinC
25 / sin37 = c / sin112.934
25Sin112.934 = cSin37
c = 25Sin112.934 / Sin37
c = **38.257**

==========================================================
A = 37          a = 25
B = 30.366    b = 21
C = 112.934  c = 38.257    
===========================================================
2)
call 'a' 21 therefore 'A' is 37'b' = 25

so 21 / sin37 = 25 / sinB = c / SinC
21 / sin37 = 25 / sinB
cross multiply,
21SinB = 25Sin37
B = ArcSine((25Sin37)/21)
B = **45.762**

3 internal angles of a tryangle = 180,
therefore C = 180-45.761-37
C = **97.239**

a / SinA = c / SinC
21 / sin37 = c / Sin97.239
c = ((21Sin97.239)/Sin37)
c = **34.616**


==========================================================
A = 37        a = 21
B = 45.762  b = 25
C = 97.239  c = 34.616
===========================================================

NOTE the other resonce u have used cosine rule and didnt distinguish between your unintentional ambiguity
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  1296 People Browsing
Related Images
  
 625
  
 329
  
 334
Your Opinion
Who's your favorite biologist?
Votes: 586