How do I find the missing angles of this triangle using the law of cosines?

Question

asnaseer · Answer

you can find the missing side using the cosine rule. the rule is described here: http://www.ucl.ac.uk/mathematics/geomath/trignb/trig12.html

asnaseer · Answer

you can then use the sine rule to find the missing angles. the sine rule is described here: http://www.y-maths.co.uk/trisincosrl.htm

anonymous · Answer

Okay, so I calculated for the side and I got 1.35. But I just don't know how to start off finding the angles now...

asnaseer · Answer

have you looked at the link for sine rule?

anonymous · Answer

So do I start with 3/sin(a) = 1.35/sin(15) to find angle a?

asnaseer · Answer

yes

anonymous · Answer

Okay, I got:

sina=(3(sin15))/1.35 = .575?

It feels wrong to me... >_<

asnaseer · Answer

its not wrong - now just take the inverse sin to get the angle.
remember to work in degrees.
once you have this, you can get the last angle by noting the angles of a triangle add up to 180

asnaseer · Answer

yw - I'm glad I was able to help :)