Expert: Ahmed Salami - 10/27/2009

Question
I need help with this problem, please!

For each of the triangles ABC, information is provided. State which case (AAS, ASA, SSA, SAS, or SSS) applies in solving each triangle and state which law to use.



(a)     A = 36 degrees, b = 50, and c = 30.





(b)     A = 55 degrees, a = 22, and c = 18.



Thank you!


Answer
Hi Cindy,
a)This triangle has two sides and an angle given. So i take it to be SAS, if i understand your shorthand.
The first thing to do is find the third side a by using the Cosine Rule and then continue to find angles B and C using the Sine Rule since you'd then have one side and its angle i.e a and A.

b)This triangle also has two sides and an angle given but the difference with this one is that there is one side and its angle (a and A) which means that you first need to find angle C using the Sine Rule, use the fact that A+B+C = 180 degrees to find B and then use the Sine Rule again to find side b.

Regards