What triangular or fan-shaped landform is created when a major river slows down dramatically and deposits sediment as it flows into a larger, slower body of water, such as an ocean or lake?

💡 Explanation:

A river delta is a depositional landform created at the mouth of a river. As the river enters a standing body of water (like a sea or lake), its velocity drops rapidly, causing it to drop its suspended sediment load, building up the characteristic delta shape.