Pentagon
9 sides
An object with nine corners (and therefore nine sides) is a nonagon.
The prefix of 9 is "non" For example, a nonagon is a two-dimensional shape with 9 sides.
You multiply all three dimensions. This only applies for prisms. For example, for a prism with sides 3, 5, and 9, you multiply the dimensions (3*5*9) = 135 units cubed.
Not sure about nonogonal, but nonagonal means refering to, or of a nonagon which is a plane object with 9 straight sides and 9 vertices.
An object that is nearly a rhombus. Foe example a quadrilateral whose sides are x, x, x and 0.99x units.
There is no such thing as an object with two sides.
Concave means that there is a dip in the object, like it has caved in. Bi-concave means that it is dipped in on two sides of the object. A good example is a red blood cell. It is a bi-concave disk - it has dips on two sides of it.
[object Object]
They are called sides.
it is an object that does not have an explanation for the sides