Răspuns:
Explicație pas cu pas:
CD=34
AB=64
AD=40
a. DE║BC
CD║EB⇒ DE=BC si CD=EB
BE=34
AB=64⇒ AE=64-34=30
In ΔDAE aplicam Pitagora
DE²=AD²+AE²
DE²=1600+900=2500
DE=50
b. Notam DQ=x⇒ QE=50-x
TRasam QR║AB
DQ=CR
Aplicam Teorema lui Thales
[tex]\frac{CQ}{QA} =\frac{CR}{RB} \\\frac{CQ}{CA}=\frac{CR}{BC}=\frac{QR}{AB}[/tex]
[tex]\frac{CR}{50}=\frac{34}{64} \\CR=\frac{34\cdot 50}{64} =26,56<27[/tex]
CR=DQ=26,56<27