Expert: Sherman D. - 7/7/2006

Question
my question has to do with sines and cosines. i dont really understand them at all, so i was wondering if you could explain how they work. and then theres a problem that i need to know how you get the answer. i had a few people try to explain but its like right over my head

its a triangle, a right triangle , the right angle is on the bottom left corner, its labled as C

the straight above it ( the top left corner) is labled as A

and then horizontil from C is labled as angle B

the side AB is labled as c
the side CB is labled as a
the side ac is labled as b


and the question it asks :

what if angle B is 40 degrees and a = 12, what is b?

i really need to know how to do these problems, so  alot of detail would help, cuz i cant find anyone so far who can help me. thanks

Answer
tanB = opposite/adjacent

go from angle B, the side opposite to that, would be side "b", the adjacent(not the opposite and not the hypothenuse) which would be "a".

tanB = (b/a)
b = a * tanB
b = 12 * tan(40)
b = 10.069

For info on how this stuff works, go to

http://mathforum.org/dr.math/faq/formulas/faq.trig.html

www.math.com/tables/trig/identities.htm