from math import tan,pi,radians

a,b,x = list(map(int,input().split()))

ok = 0

ng = 90

if 2*x >= a**2*b:

    while ng-ok > 10**(-7):

        mid = (ok+ng)/2

        if a*a*b-a**3*tan(radians(mid))/2 >=x:

            ok = mid

        else:

            ng = mid

else:

    while ng-ok > 10**(-7):

        mid = (ok+ng)/2

        if a*b**2 > 2*x*tan(radians(mid)):

            ok = mid

        else:

            ng = mid



print(ok)
from math import atan,pi



a, b, x = list(map(int, input().split()))

if a**2*b < 2 * x:

    print((180 * atan(2 * (a ** 2 * b - x) / (a ** 3)) / pi))

else:

    print((180 * atan(a * b ** 2 / (2 * x)) / pi))

from math import tan, pi, radians

a, b, x = list(map(int, input().split()))
ok = 0
ng = 90
if 2 * x >= a**2 * b:
    while ng - ok > 10 ** (-7):
        mid = (ok + ng) / 2
        if a * a * b - a**3 * tan(radians(mid)) / 2 >= x:
            ok = mid
        else:
            ng = mid
else:
    while ng - ok > 10 ** (-7):
        mid = (ok + ng) / 2
        if a * b**2 > 2 * x * tan(radians(mid)):
            ok = mid
        else:
            ng = mid
print(ok)

from math import atan, pi

a, b, x = list(map(int, input().split()))
if a**2 * b < 2 * x:
    print((180 * atan(2 * (a**2 * b - x) / (a**3)) / pi))
else:
    print((180 * atan(a * b**2 / (2 * x)) / pi))

-from math import tan, pi, radians +from math import atan, pi -ok = 0 -ng = 90 -if 2 * x >= a**2 * b: -    while ng - ok > 10 ** (-7): -        mid = (ok + ng) / 2 -        if a * a * b - a**3 * tan(radians(mid)) / 2 >= x: -            ok = mid -        else: -            ng = mid +if a**2 * b < 2 * x: +    print((180 * atan(2 * (a**2 * b - x) / (a**3)) / pi)) -    while ng - ok > 10 ** (-7): -        mid = (ok + ng) / 2 -        if a * b**2 > 2 * x * tan(radians(mid)): -            ok = mid -        else: -            ng = mid -print(ok) +    print((180 * atan(a * b**2 / (2 * x)) / pi))