are sine, cosine, and tangent only used for right triangles in trigonometry?
No. They are used for ALL triangles.
Hi Meelelion,
Welcome to the forum :)
What #1 said is true, they can be used for a whole range of problems but when you learn that
\(tan\theta=\frac{opp}{hyp}\)
etc,
That ONLY applies to right angled triangles :)
+10 
