The problem can be set up any way you want.
For example: calculate the force of gravity from a uniform sphere at a distance two radii from the center of mass.
Or, calculate the force of gravity 1 mile above a mass shaped like a brick 1000 miles long, 300 miles wide, and 200 miles thick.
Or, calculate the force of gravity 1 mile above a mass that is one mile thick and infinitely wide and infinitely long.
Like that.