Question

ΔABC has three sides with these lengths: AB = 9, BC = 40, and CA = 41. What is the value of cos C?

Answer 1

41*41 = 1681
40*40 = 1600
9* 9 = 81
so a^2 = b^2 + c^2
1681 = 1600 + 81
1681 = 1681 ...it's right triangle

CA = 41 = Hypo.
cosC = Adj / Hypo
cosC = BC / CA = 40/41

answer
cosC = 40/41

Answer 2

Answer:

The correct answer is

C 40/41

Step-by-step explanation: