def calc_area(type, a, b, c=None):
    if type == 1:
        result = a * b
        msg = '사각형'
    elif type == 2:
        result = a * b / 2
        msg = '삼각형'
    elif type == 3:
        result = (a + b) * c / 2
        msg = '평행사변형'
    return result, msg


def say():
    print('넓이를 구해요')


def write(result, msg):
    print(msg, '넓이는', result, 'm제곱 입니다.')