 To compensate for the lack of a table of chords, mathematicians of Aristarchus' time would sometimes use the statement that, in modern notation, sin "α"/sin "β"  Hipparchus was the first to tabulate the corresponding values of arc and chord for a series of angles.Although it is not known when the systematic use of the 360° circle came into mathematics, it is known that the systematic introduction of the 360° circle came a little after Aristarchus of Samos composed "On the Sizes and Distances of the Sun and Moon" (ca.260 BC), since he measured an angle in terms of a fraction of a quadrant.