Between two mirrors \(AB\) and \(AC\), forming a sharp angle two points
\(D\) and \(E\) are located. In what direction should
one shine a ray of light from the point \(D\) in such a way that it would reflect off
both mirrors and hit the point \(E\)?
If a ray of light comes towards a surface under a certain angle, it is
reflected with the same angle as on the picture.