isosaleez triangel, base=6 & both base angels=45 deg
That impli top angel=90 deg.
draw vertikal line from middel av base...it go thru top point
this triangel hav base=3.
hite=base*tan(45 deg)=base=3
so triangel points at (0,0), (6,0), & (3,3)
area=3*6=18