A 9-sided shape is known as a nonagon.
In 2-d, a heptagon.
A regular polygon with an even number of sides.
An octagon.
I cannot think of any 2-d shape. The 3-d shape with four faces is a tetrahedron.
-6
Nonagon
How about a triangle which is a 2 dimensional shape with 3 sides
A quadrilateral is a 2D shape that has 4 sides
A 2-D shape with seven sides is called a HEPTAGON.
A dodecagon has 12 sides.
-2
A square
Hexagon
a pentagon
any 2-D shape could have a perimeter of 9cm. One example is a square with sides of 9/4 cm.
In 2-d, a heptagon.
Yes * * * * * Not true! A circle is a 2-d shape that is not a polygon. A polygon must have sides that are straight lines. A 2-d shape need not have straight sides.