Tolong jawab no.2 saja

Sin 60°=DE/AD
½√3=DE/18
DE=½√3.18=9√3
AE²=AD²-DE²
=18²-(9√3)²
=324-243
AE=√81=9
AB=12+9=21
Luas=AB x DE
=21 x 9√3
=189√3