a) CF perpendicular BD AE perpendicular BD
BC perpendicular DC
AD perpendicular DC
AD perpendicular AB
BC perpendicular AB
b)BC=3/4 × AB => BC=6 cm
Perimetrul=2(AB+BC)=2 × 14cm=28cm
Aria=AB×BC=48cmpatrati
c) Triunghiurile sunt congruente (caz ULU)
d) BD=diagonala / =>A.ABD=24cm2
Aria=48cmpatrati/
e)BDpatrat=ADpatrat+ABpatrat
BDpatrat=100cmpatrati
BD=10cm
=>AE=AD×AB/BD=4.8 cm (cm2=cmpatrati) :) Succes!!