Answer:
96 inches^2
Explanation:
Using pythagorean theorem, you can find half the length of the other diagonal.
10^2-6^2=64
√64=8
6*8*2=96
There are 4 triangles and the formula for the area of a triangle is (1/2)bh so you multiply by 2 for 4 triangles.
Also I assumed that the shape was a parallelogram.