Because it has 5 (five) sides
yes a pentagon is a rigid shape * * * * * I am afraid that it is not.
It is a Pentagon.
A shape with 5 sides is called a pentagon.
A five sided shape is called a pentagon.
pentagon
They are both the same. Pentagon is just a shorter way of saying the pentagon building. As for if you meant the shape pentagon, it is called the pentagon because it's shape is a pentagon.
This is a misguided question since a pentagon is NOT a rigid shape.
It is pentagon
Pentagon
has to be pentagon
A pentagon is a shape that has 5 sides.
Five sided shapes are called Pentagons