Posted by Janie on .
A=30 degrees, a=9 and b=8. Find the missing sides/angles. I did cos39=x/8 and reduced that to 8cos39=x. I got 6.92. But that's not a valid answer, so I can't go from there. What did I do wrong? Can you show me how to get the other answers as well, please?
Law of sines:
a/SinA = b/SinB
solve for B from that.
solve for C knowing A and B, and the sum of angles is 180
Then, find c with the law of sines, or law of cosines.
If the sine of an angle is 3/5 and the angle is not in quadrant 1, what are the remaining five trigonometric values for that angle?