AR=TRQ\mathrm {AR=\frac{TR}{Q}}AR=QTR
AR=ATQ\mathrm {AR=\frac{AT}{Q}}AR=QAT
AR=ACQ\mathrm {AR=\frac{AC}{Q}}AR=QAC
AR=TPQ\mathrm {AR=\frac{TP}{Q}}AR=QTP