Problem 9.25. Compute the volume of a sphere of a equilateraltrangle based pyramid (a tetrahedron) with side base b and height 12. Problem 9.26. Compute the volume of a solid with base the region between 3; = 3:2 and y = .r3 for :e 2 0 and cross sections equilateral triangles perpendicular to the base and above the base. Problem 9.27. Compute the volume of a solid with base the region between 3; = $2 and y = r3 for a: 2 0 and cross sections semidisks perpendicular to the base and above the base. Problem 9.28. Compute the volume of the solid obtained by revolving around the maxis by 27r (i.e. a full rotation) the region between the graph ofy=2m2 andy=sc2. and forsc20