Question

CORRECT + BEST EXPLAINED ANSWER GETS BRAINLEST (50 POINTS)

Answer 1

Answer:

Option A. is the correct option.

Step-by-step explanation:

In the given triangle ABC, sides BC = a, AB = b and AC = c

Now we know as per cosine rule for all three sides of the triangle.

c² = a² + b² - 2ab cosC

a² = b² + c² - 2bc cosA

b² = a² + c² - 2ac cosC

Therefore Option A. c² = a² + b² - 2ab cos C is the answer.

Answer 2

Answer is A.

Law of cosines:

c^2 = a^2 + b^2 - 2ab cos(C)

P.S If you need others:

a^2= b^2 + c^2 - 2bc cos( A)

b^2= a^2 + c^2 - 2ac cos(B)

Hope it helps