Question

if j is 21 inches, k is 12 inches, and angle M measures 62 degrees, then find m using the Law is Cosines. round your answer to the nearest tenth

Answer 1

Answer:

18.7

Step-by-step explanation:

The Law of Cosines is $c^2=a^2+b^2-2ab cos(C)$, where c is the unknown side length of a triangle, a and b are the remaining two side lengths, and C is the angle opposite to side c. To answer this question just plug in the known values:

$m^2=21^2+12^2-2(21)(12) cos(62)$

Simplify:

$m^2=441+144-504 cos(62)$

$m^2=585-504 cos(62)$

$m=\sqrt{585-504cos(62)}$

m≈18.665...

When rounded to the nearest tenth, m=18.7