If `R = S/I`, where `S` is a polynomial ring, then the degree of `R` is by definition the degree of `I`, or the degree of the `S`-module `R`. See degree(Module) for more details.

i1 : R = QQ[a..d]/(a*d-b*c, b^2-a*c, c^2-b*d) o1 = R o1 : QuotientRing |

i2 : degree R o2 = 3 |