ABCD-romb
m(<BAD)=60*---> Tr. BAD=echilateral.-->d1(BD)=18cm.
O-intersectia diagonalelor si mijlocul lor.-->AO=OC=AC/2 ;BO=OD=BD/2
BO=OD=9cm.
Tr. AOD-Dr. ; m(<AOD)=90*
AD=18cm
OD=9cm
--->T.P. ---> OD^2+OA^2=AD^2.--->9^2+OA^2=18^2--->81+OA^2=324---> OA^2=324-81
OA^2=243
OA=√243
OA=9√3
==>AC=2*9√3
AC=18√3
Aromb=18√3*18:2
Aromb=162√3
