3
QuizMultiple Choice
Law of Sines and Law of Cosines — a Deeper Look
Question 3 • Precalculus
Which equation could be used to solve for the length of side c, given a = 5, b = 12, and C = 72°? [Not drawn to scale]
Answer
A
square of c = square of 5 + square of 12 minus 2(5)(12) cosine 72 degree
B
square of c = square of 5 + square of 12 + 2(5)(12) cosine 72 degree
C
square of c = square of 5 minus square of 12 minus 2(5)(12) cosine 72 degree
D
square of c = square of 5 minus square of 12 + 2(5)(12) cosine 72 degree