Talɣa:Aggur:Tusnakt/Anɣmis g Lqist n ɣassa

Fig. 1

Ɣ taskriɣmrt, Asaḍuf n id kusinus (ittawsan ula s yism n tanfalit n kusinus nɣ askkud n Al Kaci) tga yan usaḍuf nna ismunn tiɣziwin n tasgiwin n kra n umkṛaḍ d kusinus n yan zɣ tiɣmriwin. S uswuri n tirra zund tin Fig. 1, asaḍuf n iwankn n id kusinus

$c^{2}=a^{2}+b^{2}-2ab\cos \gamma ,$

maɣ $\gamma$ tga tiɣmrt lli illan gr tiɣziwin $a$ d $b$ d tasga tamuzzlt n $c$. I tawlaft ann nit rad darnɣ ilin ula:

$a^{2}=b^{2}+c^{2}-2bc\cos \alpha ,$

$b^{2}=a^{2}+c^{2}-2ac\cos \beta .$

Asaḍuf n id kusinus ar tskar asmata i askkud n Pythagor, nna ur illan dar imkṛaḍn unziɣn: iɣ tga $\gamma$ tiɣmrt taɣadant (nna dar illa 90 daraja, nɣ ${\textstyle {\pi \over 2}}$ s raḍyan), hann ${\textstyle cos(\gamma )=0}$, s ɣmk ad as iskar usaḍuf n id kusinus asmata i askkud n Pythagor:

$c^{2}=a^{2}+b^{2}.$

Ar nswurri s usaḍuf n id kusinus n id kusinus iɣ nra ad nḥasb tiɣmrt tiss kraḍt n kra n umkṛaḍ iɣ yad tawssan darnɣ snat tasgiwin d tiɣmrt nnsn iqqnn, d ula ɣ lḥsab n tiɣmriwin n kra n umkṛaḍ iɣ yad ttawssan darnɣ tasgiwin nns s kraḍ-itsnt. (Ɣr uggar...)