The law of cosines is used to determine the third side of a triangle
The length of the missing side is 9.3
How to determine the length of the missing side
The complete question is an illustration of the law of cosines
The law of cosine states that:
a^2 = b^2 + c^2 - 2bc * cos(A)
From the complete question (see attachment), we have:
b = 15, c = 13 and Angle A = 38 degrees.
So, the equation becomes
a^2 = 15^2 + 13^2 - 2 * 15 * 13 * cos(38)
Evaluate the exponents
a^2 = 225 + 169 - 2 * 15 * 13 * cos(38)
Evaluate the product
a^2 = 225 + 169 - 307.3
Evaluate the sum and the difference
a^2 = 86.7
Take the square root of both sides
a = 9.3
Hence, the length of the missing side is 9.3
Read more about law of cosines at:
https://brainly.com/question/4372174
