MN || AC=>m(∡BNM)=m(∡BAC)
PM || AB=> m(∡CPM)=m(∡CAB)
ΔNBM≡MPC
=>m(∡BNM)=m(∡CPM)=>m(∡ANM)=m(∡APM) (1)
m(∡BMN)=m(∡PMC)
m(∡NMP)=180°-m(∡BMN)-m(∡PMC)
m(∡BMN)=m(∡AMP)
m(∡PMC)=m(∡APN)
m(NAP)=180°-m(∡AMP)-m(∡APN)=>m(NAP)=180°-m(∡BMN)-m(∡PMC)
=>m(NAP)=m(∡NMP) (2)
Din (1) si (2) =>NAPM paralelogram deoarece are unghiurile opuse congruente
