triangle

import math

a = int(input("A: "))
b = int(input('B: '))
c = int(input("C: "))


def checkValidity(a, b, c):
    if (a + b <= c) or (a + c <= b) or (b + c <= a):
        return False
    else:
        return True

def triangle(a, b, c):
    if checkValidity(a, b, c) == 0:
        print("This is not a triangle")
    else:
        P = a + b + c
        P2 = P/2
        S = math.sqrt(P2 * (P2 - a) * (P2 - b) * (P2 - c))
        print("Perimeter: " + str(P))
        print("Areas: " + str(S))

triangle(a, b, c)