Answer:
25°
Step-by-step explanation:
Law of sines is:
a / sin A = b / sin B = c / sin C
Law of cosines is:
c² = a² + b² − 2ab cos C
Since we know 3 sides and no angles, we need to use law of cosine. We can rearrange the variables to get another version:
a² = b² + c² − 2bc cos A
Plugging in values and solving for A:
6² = 12² + 14² − 2(12)(14) cos A
cos A = 19/21
A ≈ 25°
