a open figure 8
The "figure" is the gravitational constant.
No.
A square.
No.
personification
Strictly speaking, any 3d figure with anything besides 6 sides cannot consist of rectangles. However, the name for an 8-sided figure is "octahedron".
It's not a oval its a strait line.
triangular prism
Please don't write "the following" if you don't provide a list. We can't guess that list.
... mass and speed.
Solid figures are normally classed as 3 dimensional objects