Which of the following phrases best describes the law of cosines? choose the correct answer. a. the length of a side of a triangle is equal to the sum of the squares of the remaining two sides, minus twice the product of the two remaining sides and the cosine of the angle between them. b. the length of a side of a triangle is equal to the sum of the squares of the remaining two sides, plus twice the product of the two remaining sides and the cosine of the angle between them. c. the square of any side of a triangle is equal to the sum of the squares of the remaining two sides, plus twice the product of the two remaining sides and the cosine of the angle between them. d. the square of any side of a triangle is equal to the sum of the squares of the remaining two sides, minus twice the product of the two remaining sides and the cosine of the angle between them.