# Law of cosine

• Jul 12th 2009, 02:48 PM
jordangiscool
Law of cosine
a = 4
b = 6
theta = 30

find the other sides/ angles
• Jul 12th 2009, 03:20 PM
skeeter
Quote:

Originally Posted by jordangiscool
a = 4
b = 6
theta = 30

find the other sides/ angles
if $\theta$ is between sides $a$ and $b$, then you should be able to find side $c$ using a straight application of the law of cosines.
once you find side $c$, then use the law of sines to find another angle ... the third angle can be found using the fact that all three angles sum to 180 degrees.