Recent content by xavierhart

So I worked out a=b cos C + c cos B. Because the altitude to BC divides a into b cos C and c cos B.. Makes perfect sense now that I look at it. Although, still having trouble getting to the addition formula. I've gone through the proof of sin(A+B) but not able to get there from the Law of Sines...

I'm attempting to self study mathematics. Will be starting college next year and recently got a good score on the SAT Math 2 (~700). I bought "Geometry Revisited" by Coxeter and Greitzer, hoping to gain a bit more knowledge of Geometry. I got stuck on the first question! Until now, all the...