The sedimentary rock made of large, angular pieces of sediment is called breccia.

Here's why:

* Angular Fragments: Breccia is characterized by its angular, sharp-edged fragments. This indicates that the pieces were not transported far from their source before being cemented together.

* Size: The fragments in breccia are typically larger than 2 millimeters in diameter, which is considered coarse-grained.

Let me know if you have any other questions about sedimentary rocks!