Question

va rog dau 35 de pcte si coronita ptr ex 13 si 14

Answer 1

13.
Avem,m(∡DBC)=180°-60°=120°
DB≡BC(ipoteza)
=>ΔDBC,isoscel=>m(∡BDC)=m(∡BCD)=(180°-120°)/2
=>m(∡BCD)=30°

14.
Avem,AC,cateta,opusa,unghiului,de,30°=>AC=BC/2=2,5cm
CD=DB=2,5cm(ipoteza)
m(∡ACD)=60°(180°-90°-30°)
=>ΔACD-echilateral
=>P=2,5x3=7,5cm