Law of cosines: a2 = b2 + c2 – 2bccos(A) What is the measure of N to the nearest whole degree? 35° 45° 55° 65° The triangle sides are 7 4 5.74

Answer:
option C
N ≈ 55°
Step-by-step explanation:
Given in the question a right angle triangle.
To calculate the angle N, we will use following formula
a² = b² + c² -2bcCos(A)
here,
a = 5.74
b = 4
c = 7
A = N°
Plug values in the formula
5.74² = 4² + 7² -2(4)(7)COS(N)
32.95 = 16 + 49 - 56COS(N)
32.95 = 65 - 56COS(N)
32.95 - 65 = - 56COS(N)
-32.05 = - 56COS(N)
minus will cancel out
32.05 = 56COS(N)
COS(N) = 32.05/56
COS(N) = 0.57
N = [tex]cos^{-1}[/tex](0.57)
N = 55.08°
N ≈ 55°
Answer:
C. 55
Step-by-step explanation:
5.74^2 = 4^2 + 7^2 -2(4)(7)cos(N)
32.9 = 65 -56cos(N)
-32.1 = -56cos(N)
-32.1/-56 = cos(N)
cos^-1 = 55.0253
m angle N = 55