How do I show working using sine, cosine and tangent for any angle?

Answer 1

Do you mean the sine rule and the cosine rule or just trigonometry related to SOHCAHTOA?

I'm assuming SOHCAHTOA. where sin= Opp/Hyp, Cos=Adj/Hyp and Tan= Opp/Adj. If you have a triangle and need to find the angle a, you would be given two sides of the triangle - for example the opposite side and the adjacent side. You then look at SOHCAHTOA and see that if you have the opposite and adjacent you use Tan

so write Tan a = Opposite/Adjacent
= 7/8 (For example) fill in numbers!
so a= InvTan 7/8
a=86 (made up! cos no calc!)

If you have an angle and a side, you need to find the other side and you do it as follows.
Sin 70= Opp/Hyp
Sin 70 = Opp/9
9Sin 70 = Opp

Just to make sure the opposite is always the side on the other side of the angle (opposite it!) the hypotenuse is always the longer of the remaining sides and the adjacent is whats left!

Hope that is kind of clear to you!

Answer 2

Well that's kind of an open ended question, seeing as you haven't given an example, but I'll try my best to answer it.

Your working for a question using the sine rule would look something like:

a/sinA=b/sinB
therefore: a/sin35=25/sin40
therefore: a=(25*sin35)/sin40
therefore: a=(25*0.57)/0.64
therefore: a=22.3 degrees

So the basic steps are:
1. Write out the eqaution you will use.
2. Substitute in the terms you know.
3. Work out the terms (i.e. calcualte what sin(x) is)
4. Rearrange to find your unknown.

NB Steps 2 and 3 can be done the other way around, as I did in my example. It depends on your preference.

Answer 3

Silly Old Herry Caugt A Herring Trailing Off America
Sin Opp Hyp Cos Adj Hyp Tan Opp Ady
S=O/H
C=A/H
T=O/A

thats the method i used in school

Good Luck

Answer 4

Hi >
Just a trick I used to use :
"Sir Olivers' Horse Came Ambling Home, Tired Out Again"
Sounds daft, but it helped to just go :
S=O/H, C=A/H, T=O/A
Letters being Sine, Cosine & Tangent
Opposite, Hypotenuse, & Adjacent
Just a thought
Bob