```
class Triang:
    def __init__(self, a, b, c):
        self.valido = None
        self.classificacao_lado = None  # Equilátero, Isósceles, Escaleno
        self.classificacao_angulo = None  # Retângulo, Obtusângulo, Acutângulo

    def istriang(self):
        if a >= b+c or b >= a+c or c >= a+b:
            self.valido = False
        self.valido = True

    def classificar_lado(self):
        if a == b == c:
            self.classificacao_lado = 'equilatero'
        if (a == b and a != c) or (a == c and a != b) or (b == c and b != a):
            self.classificacao_lado = 'isosceles'
        else:
            self.classificacao_lado = 'escaleno'

    def classificar_angulo(self):
        if a**2 == b**2 + c**2:
            self.classificacao_angulo = 'retangulo'
        if a**2 > b**2 + c**2:
            self.classificacao_angulo = 'obtusangulo'
        if a ** 2 < b ** 2 + c ** 2:
            self.classificacao_angulo = 'acutangulo'

A, B, C = [float(item) for item in input().split()]  # 5 5 5
triangulo = Triang(A, B, C)
triangulo.classificar_lado()
triangulo.classificar_angulo()
print(triangulo.classificacao_lado)
print(triangulo.classificacao_angulo)

```

I'm creating a triangle class, but when doing the comparisons with the sides (a, b, c) something is going wrong and I don't understand.

```
NameError: name 'a' is not defined

```

why am i getting this error? obs: "a", "b", "c" are the sides of my triangle