Law of Sines and Cosines

Wow, it's all coming full circle (so to speak). Just when we've learned to use - and even appreciate - the simplicity of radians and right triangles, Trig up and turns things on us once again by forcing us back into the land of degrees and calculators at the same time the right triangles aren't even right anymore. That's crazy! Despite the u-turn, most of my students seem to actually appreciate the Law of Sines & Law of Cosines because they're happy to be back to working with "normal" triangles, and for them that kind of makes up for having to learn new formulas and the complexities of "The Ambiguous Case". As usual, in this chapter I'll be bringing a no-nonsense approach to the Law of Sines and Law of Cosines, based on years of tutoring this to get kids through it with a minimum of confusion.

Basic Law of Sines problems

There are two kinds of Law of Sines problems. "Easy" ones involve AAS and ASA, and non inverse trig functions. "Hard" refers to SSA, a.k.a. "The ambiguous case", the subject of the next video.

The Law of Sines "Ambiguous Case"

If you haven't come across this in class yet, you pretty much need to watch the video to see why it's ambiguous. Suffice to say, they should have called it the "twice as much work" case!

Law of Cosines

In my tutoring experience, students have a much easier time with Law of Cosines problems because it's just plug-and-chug. No burn questions for this one!