The base of the solid S shown in is the bounded region enclosed by the graphs of y = x', y = 6 while the cross-sections of S' perpendicular to the y-axis are equilateral triangles. Find the volume of S. 1. volume = 18v2 cu. units 2. volume = 9 cu. units 3. volume = 9V3 cu. units 4. volume = 9v2 cu. units 5. volume = 18 cu. units 6. volume = 18V3 cu. units