The answer is A. Here's how you get it. Law of cosines here looks like this:
17^2 = 22^2 + 30^3 - [2(22)(30)cosA]; which simplifies to 289=484+900-1320(cosA). Doing that math gives you 289 = 1384 - 1320(cosA), and -1095 = -1320(cosA). Divide both sides by -1320 to get
.829545 = cos A. Now use the inverse cosine on your calculator to get the missing angle measure.
