A sedimentary rock made up of fragments with rounded edges is called a conglomerate.

Here's why:

* Rounded edges: Indicate that the fragments have been transported a significant distance, causing them to be worn down and smoothed.

* Fragments: Conglomerates are composed of larger pieces of rock (larger than sand grains), known as clasts.

* Sedimentary: They form from the accumulation and cementation of sediments.

If the fragments were angular, the rock would be called a breccia.