The answer to your question is
A = 29.6°
B = 115.4°
C = 35°
Step-by-step explanation:
Process
1.- Use the Cosines law to answer this question
c² = a² + b² - 2abcosФ
Solve for cos Ф
cos Ф = (c² - a² - b² )/ -2ab
Substitution
cosФ = (7² - 6² - 11²) / (-2)(6)(11)
cosФ = (49 - 36 - 121) / -132
cos Ф = -108 / -132
cos Ф = 0.818
Ф = 35° = C
Find B
cos Ф = (b² - a² - c²) / (-2ac)
cos Ф = (11² - 6² - 7²) / (-2)(6)(7)
cos Ф = ( 121 - 36 - 49) / -84
cos Ф = 36 / -84
cos Ф = -0.429
Ф = 115.4° = B
2.- Find a
The sum of the internal angles in a triangle equals 180°
A + B + C = 180
A + 115.4 + 35 = 180
A = 180 - 115.4 - 35
A = 29.6°