In order to apply the law comes of cosines to find the length of the side of a triangle, is it enough to know which of the following? A. The area of a triangle
B. The lengths of two of the triangle's sides and the measure of the angle between them
C. At least two of the angles of the triangle and the length of one of its sides

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  B. The lengths of two of the triangle's sides and the measure of the angle between them

Step-by-step explanation:

The usual formulation of the law of cosines is something like this:

  c² = a² +b² -2ab·cos(C)

where 'c' is the side opposite angle C, and 'a' and 'b' are the other two sides. That is, to use this formula directly, one needs two side lengths and the measure of the included angle.

Additional comment

One can use the law of cosines to solve a triangle when any two sides and one angle are known. The use of the formula will give a quadratic in the unknown side length, if it is not the side opposite the known angle. As with the law of sines, if the angle is opposite the shorter of the two given sides, there may be two solutions for the length of the third side.

215.92 dollars is the answer

2x^2+5x+17

your welcome. : )