57.6 in2 I think
so the height of the parallelogram, using the given information and trigonometry: 6.4 * sin(45°) ≈ 4.5 in
lastly you have to find the area of the parallelogram by multiplying the base and height: 12.8 * 4.5 ≈ 57.6 square inches
correct me if I’m wrong & hope this helps ^^