def triangle_area():
    a = float(input("Enter the length of the first side: "))
    b = float(input("Enter the length of the second side:"))
    c = float(input("Enter the length of the third side: "))
    s = (a+b+c)/2
    area = (s*(s-a)*(s-b)*(s-c))**0.5
    print('The area of the triangle is %0.2f' %area)
    return triangle_area
triangle_area()
