from math import sqrt, pi
# 1 Задача
a = 3
b = 5
c = sqrt(b**2-a**2)
s = c*a/2
print(s)
# 2 Задача
a = 8
b = 4
r = 2
st = sqrt((b/2)**2+r**2)
sc = pi*r**2
sr = a*b
s = st + sr - sc
print(c)
