Răspuns:
AB²+AC²=16+12=28=(2√7)²=BC²=>BC ipotenuza =>din reciproca teoremei lui Pitagora=>triunghi dreptunghic
h=AD=(AB·AC)/BC=(4·2√3)/2√7=(4√21)/7cm → teorema inaltimii →h=(c₁c₂)/ip
AB²=BD·BC
16=BD·2√7
BD=(8√7)/7cm
CD=BC=BD=2√7-(8√7)/7=(6√7)/7cm → teorema catetei
