Question #f1f7e

1 Answer
Douglas K.
Feb 13, 2018

#A ~~ 2.29417" rad or "131.4^@#

Explanation:

Use the notation where the side is labeled with lowercase letters, a, b, and c, and the angles opposite side are labeled with the corresponding uppercase letter A, B, and C, #c = 9.7#, #b = 13.6#, and #a=21.3#

One of the equations for the Law of Cosines is:

#a^2=b^2+c^2 - 2bc cos(A)#

Solving for #angleA#:

#A = cos^-1((b^2+c^2-a^2)/(2bc))#

#A = cos^-1((13.6^2+9.7^2-21.3^2)/(2(13.6)(9.7)))#

#A ~~ 2.29417" rad or "131.4^@#

Related questions
Impact of this question
213 views around the world
You can reuse this answer
Creative Commons License