In a triangle ABCABCABC, side a=7a = 7a=7, b=8b = 8b=8, and c=5c = 5c=5. Find the value of cos(A)\cos(A)cos(A).
12\frac{1}{2}21
14\frac{1}{4}41
0.250.250.25
0.50.50.5