Procedure : 

1.  Take a rectangular shaped (3″ x 6″) Acrylic sheet. 
2.  Hold the Acrylic sheet with your palm without bending it. 
3.  Ask your friend to focus light with a torch light on the sheet. 
4.  Now adjust the sheet as reflected rays are caught on a wall.
5.  Now bend slowly your palm as the sheet bends inwards in the shape of concave. 
6.  Again ask your friend to focus the light. 
7.  Now bend slowly your palm as the sheet bends outwards in the shape of convex.
8.  Again ask your friend to focus the light.

Observation : 

1.  In the first case, when without bending the sheet, reflected light is not converged at one place. Because the sheet was acted as a plane mirror. 
2.  In the second case, reflected light converged at one place. Because the acrylic sheet is bent inwards and it is acted as a concave mirror. 
3.  In the third case, reflected light rays are not converged, of course they diverged with low intensity. Because the sheet was acted as a convex mirror.

Conclusion : 

Concave surfaces converge light rays and convex surfaces diverge.