There are two sedimentary rocks that are made of gravel sized particles.  We call those particles "clasts". They are distinguished from one another by the shape of the clasts which make up the rock.  Determine if the clasts are rounded or not.  This can be somewhat subjective if you are not used to looking at a lot of sedimentary rocks.  Go back to the sedimentary rock textures page and look at the examples of grain shape.  If the clasts look mostly like the very angular, angular, or sub-angular then call the clasts "angular".  If they look more like the sub-rounded, rounded, or well rounded grains then call the clasts "rounded". (Hint: you will find the "true" answer on the Rock-Cycle lab answer key)