Branches of the nile fanned out to form a, a triangle-shaped area of soil deposited by a river. (delta/cataract)

The answer would be Delta.

Explanation:

Branches of the Nile fanned out to form a Delta, a triangle-shaped area of soil deposited by a river.

The statement is - Delta.

The Nile River creates a large delta before its entry into the Mediterranean Sea, on the northern part of the territory of Egypt. Because the river is becoming very slow in this part, large amount of debris that it carries with it are deposited on its sides, thus limiting the space for the water to pass through. The waters of the Nile started to branch out in order to continue their flow, and this gradually led to a triangular shaped area of deposits with multiple branches of the river between them, known as delta.