For problem 2, you are correct in stating that a curve forms. Specifically, if we were to trace along the outer edge of the shape, then we'd form a parabola that has been tilted 45 degrees compared to the more familiar form that students are taught (where the axis of symmetry is vertical).
For more information, search out "Tangent method for parabolas". As the name implies, the tangent method draws out the tangents of the parabola which helps form the parabola itself.
Everything else on your paper is correct. You have problem 1 correct, and the table is filled out perfectly. Nice work.