Pitagora
BD = √AB² + AD² = √144 + 81 = √225 = 15 cm
BE = 2BD/3 => BE = 2·15/3 = 10 cm
BE = 10 cm => ED = 5 cm
Duc EF ⊥ BC si EG ⊥ DC
Thales
BE/BD = EF/DC => EF = BE·DC/BD = 10·9/15 = 6 cm
DE/DB = EG/BC => EG = EG·BC/BD = 5·12/15 = 4 cm
R : mai aproape este latura DC
