A solid has base on the interval 0≤x≤π along the x–axis. Above each x in [0,π/2], the cross section perpendicular to the x–axis is a square whose side length is sinx. Above each x in [π/2,π], the cross section is a rectangle whose base is sinx and whose height is three times its base. What is the volume of the solid?
a) 2π
b) π
c) 4π+12
d) 43π