Question

punctele p, b ,c ,r sunt coliniare in aceasta ordine cu [PB] congruent cu [CR].De aceeasi parte a dreptei PR se considera puctele E si F astfel incat d(E,PR)=EB,d(F,PR)-FC si d(E,PR)=d(F,PR)

Answer 1

daca d(E,PR) = EB⇒ EB⊥PR
daca d(F,PR) = FC⇒ FC⊥ PR
daca d(E,PR)  = d(F,PR)⇒ EB=FC

compar ΔEBP si ΔFCR dreptunghice
EB=FC
PB=CR⇒ C.C.⇒ ΔEBP ≡ ΔFCR ⇒ EP=FR ; ∡BEP≡∡CFR ; ∡BPE≡∡CRF

⇒PEFR -trapez isoscel⇒ ER=FP