def task7(a: float, b: float) -> str:
    """
    Function that calculates an area of a right triangle with two sides - a and b (just like Pitagoras triangle).
    Return the area as string that has two numbers after comma.

    Input: a,b -> int numbers
    Output: area of triangle as string such as: "1.23"
    """
    pole = a * b / 2
    pole_str = f"{pole:.2f}"
    return pole_str