Hi - I am having a hard time understanding how you know that the two subtriangles, as well as the entire triangle, are each 30 - 60 - 90 triangles "from the information given" as it says in the answer in the back of the book. I know that each has a 90 degree angle in it, but I don't understand how we know that the 90 degree angle at C is split into a 30 degree angle and a 60 degree angle, or how to come to this conclusion based on any other information from the question. Please help! Thanks!

Nevermind, I didn't read the whole question!!