trigonometry repost .
posted by Anon .
This is an outline that i have to use to find the solution of the question. It involves logarithms and halfangle formulas.I have worked though it but got stuck on some parts. I'd like if you look over my work.
solve the triangle for which given parts are
a=27 ,b=21 ,c=24
Now i used the cosine law and got the answers
A=73 deg 23' 55"
B=48 deg 11' 23"
C=58 deg 24' 43"
...................
okay now for this outline;
a=27
b=21
c=25

2s=73
s=36.5
sa=9.5
sb=15.5
sc=11.5
log(sa)= .97772
log(sb)=1.19033
log(sc)=1.06070

=3.22875
log s =1.56229

2)1.66646

log r =0.83323
now this part I'm having trouble with.
log r = 0.83323
log(sa) = 0.97772

log tan A/2 = 9.85551  10
A = ? << can you help me convert.
log r = 0.83323
log (sb) = 1.19033

log tan B/2 = 9.64290  10
B = ? same here my brain freezes
log r = 0.83323
log (sc) = 1.06070

log tan C/2 = 9.77253  10
C = ?
A+B+C= 180 deg 0' 2"
do they match?

that was a typo its 15.5 which makes the log entry correct.
=3.22875
log s =1.56229 subtract.

2)1.66646 <<.. then divide by 2 =

log r =0.83323
the reason why i posted the out line was because they did not match. and i didn't understand how you got the inverse tangent .

As I noted in my previous reply to the same question, I fail to understand why you are doing such elaborate steps to solve such a rather simple question.
I always understood, that "solving" a triangle involved finding any missing sides or angles.
The 3 sides were given, you used the cosine law to find the 3 angles.
So to me the triangle is "solved" at that point.
(BTW, I would have found the largest angle by using the Cosine Law, then used the Sine Law to find a second angle, then used the supplementary property to find the third angle. The largest angle would be opposite the largest side. By finding the largest angle using the Cosine Law, you avoid any ambiguous case that might result in using the Sine Law. There can only be one obtuse angle in any triangle. )
for the area, by Heron's Formula,
Area = √(s(sa)(sb)(sc))
= √((36.5)(9.5)(15.5)(11.5))
= 248.6125
Respond to this Question
Similar Questions

MATH
1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL STEPS) sin 2x  sin x = 0 2.) GIVEN: sin u = 3/5, 0 < u < ï/2 Find the exact values of: sin 2u, cos 2u and tan 2u using the doubleangle formulas. 3.)Use … 
Math
I am stuck on a problem that has to do with the double angle formulas. I have to solve this: 4sinxcosx = 1. I tried using the formula 2sinu = 2sinucosu by substituting it in like this: 2(2sinxcosx)= 1 but then I am stuck 
trigonometry
okay so i have this trigonometry problem were i HAVE to use logarithms. Now this is my work but can u help me solve it using logarithms. Find the area of the following triangles:(use logarithms) 1) c=426, A=45degrees 48' 36",and B=61degrees … 
trigonometry
1. Finde the area of the following tringles: (use Logarithms) A) a=12.7, b=21.5, c=28.6. i'm not of the answer i got. i got 127.6 if you got something different can you show me how you did while using logarithms. 
trigonometry (MathMate)
MathMate i would really appreciate if you can show me where the logarithms can be used.I know they are unnecessary and I already found the answer without them but i still have to show my work using logarithms and they just confuse … 
Trigonometry (Logarthims)
Give checks to the following two questions Use logarithms and the law of tangents to solve the triangle ABC, given that a=21.46 ft, b=46.28 ft, and C=32°28'30" without logarithms i can do this problem easily and i have. but when i … 
trigonometry
Use logarithms and the law of tangents to solve the triangle ABC, given that a=21.46 ft, b=46.28 ft, and C=32°28'30" Also Give checks. I know the use of logarithms is unnecessary but i have to show my solution by using logarithms … 
trigonometry (repost) Mathmate
I want to start by saying thank you . You have no idea how much u have helped me understand logarithms, even better then the books i have (it poorly explains the subject of trigonometry let alone logarithms and antilog). Your last … 
Trigonometry /Logarithms (brace yourself)
This is an outline that i have to use to find the solution of the question. It involves logarithms and halfangle formulas.I have worked though it but got stuck on some parts. I'd like if you look over my work. solve the triangle for … 
trigonometry
This is an outline that i have to use to find the solution of the question. It involves logarithms and halfangle formulas.I have worked though it but got stuck on some parts. I'd like if you look over my work. solve the triangle for …