a)<(EC,AB)=<(EC,CD)=<ECD=45* (pt ca trg ECD e dr isoscel)
b) in trg dreptunghic isoscel ECD stiu ca CD=6V2 rezulta ca
aplicand T.P am
x^2+x^2=(6V2)^2=36*2=2x^2 ⇒ x^2=36 ⇒ x=6 (x=EC=ED)
⇒in trg EBC , EB=BC=EC=6 ⇒ < EBC=60*
c)<(EC,AD)=<(EC,BC)=60*
d) trg EBC e echil, EM mediana⇒ EM inaltime
<(AD,EM)=<(BC,EM)=90*
e)in trg EBD stiu ca EB=ED=6 si BD=6V3(am aplicat T.P in trg BCD)
duc inaltimea EN _|_BD si am BN=6V3/2=3V3
aplic TP in trg ENB
EN^2=EB^2-BN^2=36-27=9
⇒EN=3=6/2 ⇒<EBD=30* ⇒⇒(teorema 30-60-90)
⇒<BEN=60=<BED/2⇒<BED=120*
