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

Here's why:

* Conglomerates are a type of clastic sedimentary rock, meaning they are formed from fragments of other rocks.

* The rounded edges of the fragments indicate they have been transported a significant distance and have been worn down by abrasion.

* If the fragments are angular, the rock is called a breccia, suggesting shorter transport and less weathering.