Answer
$\approx711$ square inches.
Work Step by Step
The area of half the parallelogram can be obtained by calculating the area of the triangle with sides $24.1$ and $31.4$ in and diagonal $32.4$.
Here $s=0.5(24.1+31.4+32.4)=43.95$
Hence the area of the parallelogram is: $A=2\sqrt{43.95(43.95-24.1)(43.95-31.4)(43.95-32.4)}\approx711$ square inches.