solves the square root of a triangle

Solver.py

import math

__author__ = 'Ernest'
__project__ = "MySimplePythonApplication"

class Solver:
    def demo(self):
        while True:
            a = int(input("a "))
            b = int(input("b "))
            c = int(input("c "))
            d = b ** 2 - 4 * a * c
            if d >= 0:
                disc = math.sqrt(d)
                root1 = (-b + disc) / (2 * a)
                root2 = (-b - disc) / (2 * a)
                print(root1, root2)
            else:
                print('error')

Solver().demo()