At Westonci.ca, we make it easy to get the answers you need from a community of informed and experienced contributors. Our platform connects you with professionals ready to provide precise answers to all your questions in various areas of expertise. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.

On which triangle can the law of cosines be used to find the length of an unknown side?

Law of cosines: a2 = b2 + c2 – 2bccos(A)

Triangle Q R S is shown. The length of Q R is s, the length of R S is q, and the length of Q S is 12. Angle R Q S is 36 degrees, angle Q S R is 57 degrees, and angle S R Q is 87 degrees.
Triangle Q R S is shown. The length of Q R is s, the length of R S is 7, and the length of Q S is 12. Angle R S Q is 57 degrees.
Triangle Q R S is shown. The length of Q R is s, the length of R S is 7, and the length of Q S is b. Angle R S Q is 57 degrees and angle S Q R is 36 degrees.
Triangle Q R S is shown. The length of Q R is s, the length of R S is q, and the length of Q S is 12. Angle R Q S is 36 degrees and angle Q S R is 57 degrees.


Sagot :

Answer:

  (b) Triangle QRS is shown. The length of QR is s, the length of RS is 7, and the length of QS is 12. Angle RSQ is 57 degrees.

Step-by-step explanation:

The Law of Cosines can be used to find an unknown side when that side is opposite a known angle, and the lengths of the sides of that angle are known. That will be the case when the known sides share a vertex, and the angle at that vertex is known.

View image sqdancefan