In the triangle below, determine the value of c.

http://prntscr.com/4f3nox

Can anyone help me with this? I think I've got it, but I'm not sure.

Question

In the triangle below, determine the value of c.

     http://prntscr.com/4f3nox

Can anyone help me with this? I think I've got it, but I'm not sure.

imstuck · Answer

Which trig identity did you use and how?

anonymous · Answer

There was a previous problem similar to it so I used this 

sin(40)=c/15

But I don't think it's right.

imstuck · Answer

No you're correct, that's not right.  You have the side opposite the angle, and you have the side adjacent to the angle.  Which identity uses those sides?  Sin, Cos, or Tan?

imstuck · Answer

Do you know SOHCAHTOA?

anonymous · Answer

No.

imstuck · Answer

That means "Sin-Opposite over Hypotenuse", "Cos-Opposite over Adjacent" and "Tan-Opposite over Adjacent".  Do you know which one to use now?  You have the side opposite the angle and the side adjacent to the angle.