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Subject: Re: Request for simple trig formula
From: Sam Chan (schan@XXX.XXX)
Date: Tue Apr 15 2003 - 21:19:55 EDT
Law of Cosine (good for non-right triangles)
Let A, B, and C be the three angles of a triangle. Let a, b, and c be the
lengths of the "opposite" side.
The Law of Cosine: c^2 = a^2 +b^2 -2a*b*cos(C)
For right triangles: Let C be the right angle. The long side opposite of C
is called the hypotenuse. From any non-right angled corner,
sin A = a/c where a is the length of the side opposite of the angle A and c
is the hypotenuse
cos A = b/c where b is the length of the side adjacent to the angle A and c
is the hypotenuse
Use either of these to find angle A.
Once angle A is found, angle B =90-A.
Sam
----- Original Message -----
From: "David Weilacher" <daveweilacher@XXX.XXX>
To: <NAVIGATION-L@XXX.XXX>
Sent: Tuesday, April 15, 2003 3:03 AM
Subject: Request for simple trig formula
> I need a favor.
>
> I don't recall the simple trig formulas and don't have the mental
where-with-all to find anything using a search engine. I think it is
because my mind just doesn't index the way they do.
>
> If I know the lengths of 3 sides of a triangle and one angle (90), how do
I determine the two remaining angles.
>
> I do own a fancy calculator capable of sin, cos stuff.
>
> What I would like to come away with are the side-angle-side,
angle-side-angle, and side-side-side formulas so that I can write them down
in my address book for future reference.
>
> Thank you.
>
> PS: I am attempting to solve a problem indirectly related to navigation.
>
>
> Dave Weilacher
> .US Coast Guard licensed captain
> . #889968
> .ASA instructor evaluator and celestial
> . navigation instructor #990800
> .IBM AS400 RPG contract programmer
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