Isithuthi sama-angles angu-180°/360°. Umklamo ocacile oneziqu eziphrintiwe. Sicela usithinte mayelana ne-MOQ, intengo, i-ejenti kanye nezinye izindaba zokubambisana.
Ama-Protractors kanye nama-Semicircular
Izinto: ipulasitiki esobala
Isisekelo: 10/12.5cm