Ducem,perpendiculara,din,C,pe,AB,si,notam,cu,M,piciorul,acesteia.
In,tr.de.CMB,avem,MB=4cm
m(MCB)=30(in,ipoteza,spune,ca,mB=60)
=>cateta,opusa,unghiului,de,30=ipotenuza/2=>BC=8cm
Cu,t.Pit.aflam,inaltimea,in,trapez,CM
CMpatrat+MBpatrat=CBpatrat
CMpatrat=64-16=>CMpatrat=48=>CM=4rad.din,3=AD
Aria=(B+b)h/2=(9+5)4rad.din.3/2
Aria=28rad.3mpatrati