Posted by Anon on Sunday, February 27, 2011 at 2:11am.
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"
Using the previous values,
a=21.46
b=46.28
C=322830=32.475
We have
A+B=18032.475=147.525
a+b=67.74
ab=24.82
tan((A+B)/2)=3.433633
tan((AB)/2)=tan((A+B)/2)*(ab)/(a+b)
= 1.2580863 <<.. i did this part in logarithms it was actually very easy now that i understood it. thank you!
but i cant seem to understand what u did in the following part .
(AB)/2 = atan(1.2580863)= 51.520285
AB = 103.04057
I didn't get what u did there and when i tried it i came up with different numbers. Can you please clarify the steps.
thank you for taking the time to help me. I really appreciate it.
A=(147.525103.04057)/2=22.242215°
B=(147.525+103.04057)/2=125.282785°

trigonometry (repost) Mathmate  MathMate, Sunday, February 27, 2011 at 7:21am
Sorry, it must have been a typo.
It should read:
(AB)/2 = atan(1.2580863)= 51.520285
So multiply by 2 to get
AB = 103.04057
The negative sign was because I did not choose A and B wisely. It turned out that A<B.
So if
AB=103.04057....(1)
A+B=147.525.....(2)
Add (1) and (2)
2A+0B=44.484430 => A=22.242215
Subtract (1) from (2)
0A+2B=250.56557 => B=125.282785
Notice that B>A, so AB is negative, so is arcTan((AB)/2).
Answer This Question
Related Questions
 trigonometry (repost) Mathmate  I want to start by saying thank you . You have ...
 trigonometry  Use logarithms and the law of tangents to solve the triangle ABC...
 trigonometry  Use logarithms and the law of tangents to solve the triangle ABC...
 Trigonometry  Find the exact value of tan(ab) sin a = 4/5, 3pi/2<a<pi...
 MathTrigonometry  Show that if A, B, and C are the angles of an acute triangle...
 Trigonometry /Logarithms (brace yourself)  This is an outline that i have to ...
 Trigonometry  Hello, everyone: I am working on finding the exact values of ...
 calculus  I need help on finding the local linear approximation of tan 62 ...
 trigonometry  This is an outline that i have to use to find the solution of the...
 trigonometry repost .  This is an outline that i have to use to find the ...
More Related Questions