Python:
figure = str(input())
if figure == "треугольник":
a = int(input())
b = int(input())
c = int(input())
p = (a + b + c ) // 2
S = (p*(p-a)*(p-b)*(p-c))**0.5
print(S)
if figure == "прямоугольник":
a = int(input())
b = int(input())
print(a * b)
if figure == "круг":
r = int(input())
print(3.14 * (r**2))
Traceback (most recent call last):
File "jailed_code", line 7, in <module>
p = (a + b + c ) // 2
NameError: name 'a' is not defined