import math


def get_approx_flame_length(head_fire_intensity: float):
    """ Returns an approximation of flame length (in meters).
    Formula used is a field-use approximation of
    L = (I / 300)^(1/2), where L is flame length in m and I is Fire Intensity in kW/m
    """
    return math.sqrt(head_fire_intensity / 300)