Răspuns:
B
| D
|
A___________C
BD/DC = 1/2 =>DC=2BD
BD+DC=BC=arad3
3BD=arad3
BD=arad3/3
DC=2arad3/3
AB^2 = BD•BC (t.catetei)
AB^2 = arad3/3 • arad3
AB^2 = 3a^2/3
AB^2 = a^2 =>AB=a
AC^2 = DC•BC (t.catetei)
AC^2 = 2arad3/3 • arad3
AC^2 = 6a^2/3
AC^2 = 2a^2 =>AC=arad2