Question 943227
For a triangle with an angle {{{theta}}}, they are calculated this way:
Sine Function:
	{{{sin(theta) = Opposite / Hypotenuse}}}
Cosine Function:
	{{{cos(theta) = Adjacent / Hypotenuse}}}
Tangent Function:
	{{{tan(theta) = Opposite / Adjacent}}}


How to remember? Think "{{{Sohcahtoa}}}"! It works like this:
{{{Soh}}}...
	
{{{(s)ine = (o)pposite / (h)ypotenuse}}}

...{{{cah}}}...
	
{{{(c)osine = (a)djacent / (h)ypotenuse}}}

...{{{toa}}}
	
{{{(t)an = (o)pposite / (a)djacent}}}

so, sometimes you are given an angle and side, then formulas above will help you to calculate unknown side or angle

Example: what are the sine, cosine and tangent of {{{30}}}°  ?

The classic {{{30}}}° triangle has a hypotenuse of length {{{2}}}, an opposite side of length {{{1}}} and an adjacent side of {{{sqrt(3)}}}:

Now we know the lengths, we can calculate the functions:
Sine
	  	{{{sin(30) = 1 / 2 = 0.5}}}
Cosine
	  	{{{cos(30) = sqrt(3)/2=1.732 / 2 = 0.866}}}
Tangent
	  	{{{tan(30) =1/sqrt(3)= 1 / 1.732 = 0.577}}}