In ΔABC, AB = 6√3 cm, AC = 12 cm and BC = 6 cm, then ∠B is
A
120°
B
60°
C
90°
D
45°
Correct Option:
C
Explanation
For angle B, the opposite side is AC = 12. Using the cosine rule, AC² = AB² + BC² − 2(AB)(BC) cos B. Here, 12² = (6√3)² + 6² = 108 + 36 = 144. Therefore, cos B = 0, so B = 90°.
