For this case, we have by definition the law of cosine states that:
[tex]a = \sqrt {b ^ 2 + c ^ 2-2 (b) (c) * cosine (67.4)}[/tex]
We have to:
[tex]b = 13\\c = 14[/tex]
Substituting:
[tex]a = \sqrt {13 ^ 2 + 14 ^ 2-2 (13) (14) * cosine (67.4)}\\a = \sqrt {169 + 196-364 * 0.38429532}\\a = \sqrt {365-139.8834965}\\a = \sqrt {225.1165035}\\a = 15.00388295[/tex]
Rounding off we have:
[tex]a = 15[/tex]
Answer:
[tex]a = 15[/tex]
