ΔABC
AB=2 =>AB²=4
AC=4√3 =>AC²=(4√3)²= 48
BC=2√13 =>BC²=(2√13)²= 52
4+48=52
AB²+AC²=BC² =>ΔABC -dreptunghic, mas<A=90
fie [AD] _|_ [BC]
AD-h
AD=AB* AC/BC= 2 * 4√3/2√13= 4√3/√13= 4√39/13
ΔADB, mas<D=90
BD²= AB²-AD²= 2² - (4√39/13)²= 4 - 624/169= (676-624)/169= 52/169
=>BD= 2√13/13
DC=BC-BD= 2√13 -2√13/13= (26√13 -2√13)/13= 24√13/13
