Question

In triangle abc, a = 2, b = 4 and c=2sqrt(7) find the largest angle of the triangle in degrees 60 120 150 30

Answer 1

Pre - requiste to understand my answer.
1) Cosine rule
2) Trigonometry
3) Theorem : Angles opposite to larger sides are larger.

Here, In my answer sides a, b ,c are opposite to angles A,B and C respectively.

Hope, you understand my writing ( sorry for bad writing) and it helps you.

Final answer: largest angles is C= 120°.