Law of Cosines are used when an angle and two sides are given and you have to find for the other side. Law of Sines are used when you need to find the angle of the opposite side.
Parallel structure should be used when you connect clauses with a coordinating conjunction such as: for, and, nor, or, but, so, or yet.
Some examples of this include:
Correct: Every morning, we make our bed, eat breakfast and feed the dog.
Incorrect: Every morning, we make our bed, eating breakfast and feed the dog.
I'm not 100% sure because it's been a while since I have read the book, but I want to say it's B or the second choice given.
Answer:
D) President Kennedy outlines how the world is very different, and it is important for Americans to stand together and support the United Nations in its quest for peace.
Explanation:
President Kennedy adresses the nation and the world in his inaugural speech with the idea of defending freedom and supporting the UNited Nations in the pursue of a better world, and he invites americans to get on board with the idea of helping one another, and says his famouse phrase "Do not ask what your country can do for you, ask what can you do for your country". He faces how we lived in a different world and how americans should stand together against those who are a threat to freedom and prosperity.