Thread: Finding Sin, Cos, and Tan

This is what I know:



I figured out the ninety degrees and the seventy degrees because a right angle is always ninety degrees and a triangle always adds up to one hundred eighty degrees. The problem itself just told me "A= 20 degrees and a = 12" and gave me a triangle with letters..

It doesn't even tell me where Theta is, which really confused me. Although, I assumed that the line with C on it was the Hypotenuse, the one with 12 was the adjacent line, and the b line being the opposite line.

Using that, I could only kind of figure out Tan. Because it would be "b/12." And I think you could solve that by using the formula "12 (Tan 20) = b." Is that even right? Or is there a different way to solve it..?

it's your choice as to what acute angle you want as theta ...

if you pick theta = 70, then

tan(70) = b/12 ... b = 12tan(70)

if you pick theta = 20, then

tan(20) = 12/b ... b = 12/tan(20)

once you have b, you can use Pythagoras to find c, or ...

sin(20) = 12/c ... c = 12/sin(20)

or ...

cos(70) = 12/c ... c = 12/cos(70)

So..Sine would be 351/44, right?

sine of what angle? please note that sine by itself means nothing.

also, where/how did you get the numbers 351 and 44 ?

Err...Scratch that. I messed up.