A is an area of land where a river enters lake sea?

A delta is an area of land where a river enters a lake or sea. It is formed by the deposition of sediment carried by the river. Deltas are often triangular in shape, with the apex of the triangle pointing upstream. The size of a delta depends on the amount of sediment carried by the river, the rate of subsidence of the land, and the wave energy of the lake or sea.