Question

In triunghiul ABC consideram punctual D apartinand lui AB si consideam DE parallel cu BC,E apartine lui AC. a) daca AD=3 cm,AB=9cm si AE=6cm,aflati AC. b) daca DB=12 cm,AB=16 cm si AE=5cm,aflati EC. c) Daca AB=36 cm,DE=6 cm si AD = 12 cm,aflati AE. d) Daca AB=12 cm,AC=18 cm si AE=3 cm,aflati AD.

Answer 1

a)DE||BC⇒AD/AB=AE/AC
3/9=6/AC=1/3
AC=6*3=18cm
b)DE||BC⇒AD/BD=AE/CE
AD=16-12=4cm
4/12=5/CE=1/3
CE=5*3=15cm
c)DE||BC⇒AD/BD=AE/EC
BD=36-12=24cm
12/24=AE/6=1/2
AE=6/2=3cm
d)DE||BC⇒AD/AB=AE/AC
AD/12=3/18=1/6
AD=12/6=2cm