In triangle UVW, u = 20, v = 47. and w = 60. To find m∠ W,

which law would you use? Laws of Sines or Laws of Cosines? and why?


Answer :

Answer:

We would use the Law of Cosines to solve the question.

m∠ W = 121.8°

Step-by-step explanation:

In triangle UVW, u = 20, v = 47. and w = 60. To find m∠ W,

which law would you use?

The Law we would use to find find m∠W is the Law of cosines, this is because in the question above we are given 3 known sides of a triangle and we are asked to find an unknown angle.

Law of cosines when we are to find an unknown angle =

m∠ W = arc cos [u² + v² - w²/ 2uv]

m∠ W = arccos [ 20² + 47² - 60²/ 2 × 20 × 47]

m∠ W = 121.81159°

Approximately = 121.8°