Asekkud n Ṭalis

Tawila-a tezrmer ad tili des usekkud n Talis : izirigen (BC) d (DE) id imsadaɣen ihi ikerrdisen ADE akked ABC d imeswan (semblables) d teɣzi AD, DE,EA id imẓunen ar teɣziwin AB, BC d CA

Isem n usekkud yekka-d seg amussnaw agrigi Ṭalis

Asekkud n Ṭalis d yiwen seg yisekkuden igejdanen deg tanzeggit. Yettwassen s yisem n Ṭalis n Mili, amusnak agrigi n tsuta tis 6 send talalit n Ɛisa. Asekkud-a yesskan-d assaɣen yellan gar snat n teɣdiwin n yiwen akerdis.

Aglam n usekkud

Asekkud n Ṭalis

ili akerdis ABC, d sin igazen D akked E. D seg uzrig (AB) d E seg uzrig (AC), am wakken azrig (DE) ad yili amsadaɣ ar uznig (BC).

Ihi :

$\frac{AD}{AB}=\frac{AE}{AC}=\frac{DE}{BC}$

snat n tawilat izemren ad ilin deg usekkud n Ṭalis:

• 
  seg tawalia-a nesɛa-d: $\frac{AD}{AB}=\frac{AE}{AC}=\frac{DE}{BC}$
• 
  seg tawila-a a nesɛa-d: $\frac{AD}{AB}=\frac{AE}{AC}=\frac{DE}{BC}$

Asekkud amsuɣal (réciproque) n Ṭalis

Tamsuɣalt n usekkud n Ṭalis :

Deg ukerdis ABC, ad negg belli nesɛa igazen D akked E i yellan ar [AB] d [AC]. Ma d assaɣen $\frac{AD}{AB}$ d $\frac{AE}{AC}$ ugdan, ihi izrigen (DE) d (BC) d imsadaɣen

Asekkud "taɣda n tlemmast"

ili akerdis ABC, ad negg D akked E d tilemmasin n [AB] d [AC].

ihi taɣdiwin (DE) d (BC) d imsadaɣen yarnu nesɛa : $2DE=BC$

Tamsuɣalt n usekkud n Ṭalis ad ɣ-t-efk akken d sin taɣdiwin d imesdaɣen; yarnu, asekkud n Ṭalis yettwakles id yeddu am akka :

$\frac{DE}{BC}=\frac{AD}{AB}=\frac{1}{2}$