Question

Triangular area of marshland formed by deposits of silt at the mouth or some rivers?

Answer 1

Delta

Step-by-step explanation:

Delta is a triangular region where rivers divide into small streams and then progresses to drain into a big river. Such regions possess rich alluvial and mineral soil deposits. It is the part of an old age river.

For example - the largest delta of the world is the Ganges Bhramaputra delta