Identify the correct expression for the volume of the solid whose cross-sections are equilateral triangles perpendicular to the axis and whose base is bounded by and .

Identify the correct expression for the volume of the solid whose cross-sections are equilateral triangles perpendicular to the axis and whose base is bounded by and .

Identify the correct expression for the volume of the solid whose cross-sections are semicircles perpendicular to the axis and whose base is bounded by and .

Identify the correct expression for the volume of the solid whose cross-sections are semicircles perpendicular to the axis and whose base is bounded by and .

Find the volume of the solid whose cross-sections are semicircles and whose base is bounded by the circle .

Find the volume of the solid whose cross-sections are semicircles and whose base is bounded by the circle .

Identify the correct expression for the volume of the solid whose base is bounded by , , and , and whose cross-sections are right isosceles triangles, perpendicular to the axis, with one leg on the base of the solid.

Identify the correct expression for the volume of the solid whose base is bounded by , , and , and whose cross-sections are right isosceles triangles, perpendicular to the axis, with one leg on the base of the solid.

Find the volume of the solid whose cross-sections are equilateral triangles and whose base is a disk of radius .

Find the volume of the solid whose cross-sections are equilateral triangles and whose base is a disk of radius .