Question

va rog foarte mult ma ajutati dau toate punctele si o coroana

Answer 1

Răspuns

Explicație pas cu pas:

a) daca DE║BC cfm. teoremei fundamentala de asemanare

=> AD/AB=AE/AC  <=>  3/(AD+DB)=AE/20  <=>  3/5=AE/20  => AE=3·20/5

=> AE=12cm.

b) AD/AB=AE/AC  <=> 2/12=AE/18  => AE=3cm  => EC=18cm-3cm=15cm.

c) AD/AB=AE/AC  <=>  AD/12=5/15  => AD=12·5/15 => AD=4cm.

d)AD/AB=AE/AC  <=>  AD/25=4/20  => AD=25·4/20  => AD=5cm

=> DB=AB-AD=25cm-5cm=20cm.