Explanation:
the volume of a cylinder (as any other fully symmetric 3D object) is
base area × height
the area of a circle is
pi×r²
this is in our case
pi×6²×16 = pi×36×16 = 576pi = 1,809.557368... cm³
1 liter fits into a cube of 10 cm side length (10×10×10 = 1000 cm³).
so, the paint can will contain
1,809.557368... / 1000 = 1.809557368... liters of paint.