a) EO≡EO≡EO≡EO
AO≡BO≡CO≡DO ( intr-un dreptunghi diagonalele sunt congruente si se injumatatesc)
mas ∡AOE=mas∠BOE=mas∠COE=mas∠DOE=90° ( EO ⊥(ABC),ipoteza, EO⊥orice dreapta ⊂(ABC))
caz congruenta Catetat Cateta
EA≡EB≡EC≡ED, cerinta
[EA]=√(5²+5²)=5√2=EB=.EC=ED
pt ca DO= (1/2)*√(8²+6²)=(1/2)*10=5
Perim ABCD= 2(8+6)=28
Suma muchiilor= 28+4*5√2=28+20√2, cerinta
