What is the volume of a torus with tube radius rrr and major radius RRR?
π2R2r\pi^2 R^2 rπ2R2r
2π2Rr22\pi^2 R r^22π2Rr2
2πR2r22\pi R^2 r^22πR2r2
4π2Rr4\pi^2 R r4π2Rr