Answer
$A \approx 11.6$ ft$^{2}$
Work Step by Step
$A = \frac{1}{2}absin(C)$
$A = (0.5)(6)(6)sin(40)$ (We know that both $a$ and $b$ are the same as this is an isosceles triangle)
$= (0.5)(36)sin(40)$
by GDC / calculator
$= 11.5701...$ ft$^{2}$
$\approx 11.6$ ft$^{2}$