import math
from abc import abstractmethod


class Shape:
    color = ''

    @abstractmethod
    def area(self):
        pass

    @abstractmethod
    def perimeter(self):
        pass

    @staticmethod
    def convert_to_json(obj):
        if isinstance(obj, Shape):
            result = obj.__dict__
            result['type'] = obj.__class__.__name__
            result['color'] = obj.color
            return result