this is not a solid of revolution ... it is a solid formed by similar cross-sections.

in this case, each similar cross section is a semicircle. the diameter of a semicircular cross-section is , so, the radius of a semicircular cross-section is

therefore, the representative cross sectional area as a function of x is

limits of integration will be from x = 2 to x = 3.

you have all the information you need ... set up the volume integral and evaluate.