Why are the wall of a dam is made thicker at the bottom? Expert please answer it urgent

The wall of dam is made thicker at the bottom because pressure exerted by a liquid increases with Depth . Thus as depth increases more and more pressure is exerted by water on the walls of dam . A thicker wall is required to withstand a greater pressure , therefore,the wall of the dam is made with thickness increasing towards the base I hope you will like it!!!!