Based on the answers provided, the following corrections need to be made to the 3D object:

1. Change the shape of the object from a hexagon to a square. Ensure that the square has four equal sides and four 90-degree angles.
2. Ensure that the square is slightly extruded to give it a 3D form.
3. Maintain the right triangle cutout from the bottom-right corner of the square.
4. Ensure that the corner of the triangle's right angle aligns with the square's corner.