S1 and S2 are two straight-line reflections of S1 in S2 and S2 in S1 coincide. Find the angle between both
When two straight-line reflections, S1 and S2, coincide, it implies that they are mirror images of each other with respect to a common line. In other words, S1 is a reflection of S2 and S2 is a reflection of S1, resulting in an overlap of their positions. In such a scenario, the angle between them is 0 degrees, meaning they are aligned perfectly.