A Simple Torch Model

Consider two mirrors and a light source. The mirrors form an angle φ and -φ with a horizontal axis, and the light source is located at horizontal axis and near junction of the two mirrors (see the black dot below).The light source emits light of total power P with uniform distribution. Assume the mirrors are perfect reflectors. Also assume that this system is only 2 dimensional. Find the distribution of power, dP/dθ, as a function of θ (the angle formed by light and horizontal axis after the light is out from the system)!