Two vertical plane mirrors are parallel and separated by 0.40 m. A light ray strikes the left mirror at an angle of 20° with the normal, reflects to the right mirror, and after that second reflection exits the space between the mirrors. How far along the surface of the left mirror (measured parallel to the mirror’s edge) is the point of the second impact from the point of first impact?
a) 0.27 m
b) 0.15 m
c) 0.29 m
d) 0.40 m