Re: Trigonometry, sine theorem.
- To: mathgroup at smc.vnet.net
- Subject: [mg30750] Re: [mg30719] Trigonometry, sine theorem.
- From: BobHanlon at aol.com
- Date: Sun, 9 Sep 2001 03:26:49 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 2001/9/8 3:18:14 AM, Matthias.Bode at oppenheim.de writes:
>I have a non-special triangle with sides
>
>a = 75mm, b = 67 mm, c = 117 mm.
>
>I just want to calculate the angles alpha, beta, gamma using a/b =
>sin[alpha]/sin[beta] &c. for a/c and b/c.
>
>All my attempts with FindRoot, Solve, including prior TrigToExp
>transformation were nugatory.
>
a = 75; b = 67; c = 117;
FindRoot[{Sin[alpha]/Sin[beta] == a/b,
Sin[alpha]/Sin[gamma] == a/c,
alpha+beta+gamma == Pi},
{alpha, Pi/3}, {beta, Pi/3}, {gamma, Pi/3}]
{alpha -> 0.6423734163310746, beta -> 0.5647370762223595,
gamma -> 1.934482161036359}
Bob Hanlon
Chantilly, VA USA