Two plane mirrors are inclined at an angle of 90 degree to each other calculate the number of images formed if the two mirrors are kept. Parellel to each other, at 60 degree

Dear Student,
                             The no. of images(n) formed is given  by the formula,
                                                                         $n = \left(\frac{360}{\theta }-1\right) , where \theta is the angle between mirrors.$
            Here firstly we have,   
                                                $$\begin{gathered} \theta = {90}^0, so number of images, n = \left(\frac{360}{90}-1\right) \\ =3. \end{gathered}$$
                Now, 
                                             $$\begin{gathered} \theta = 0^0, so number of images, n = \left(\frac{360}{0}-1\right) \\ =\infty (inflinite no of images) \end{gathered}$$
            And now, 
                                 $$\begin{gathered} \theta = {60}^0, so number of images, n = \left(\frac{360}{60}-1\right) \\ =5. \end{gathered}$$

Regards