Pentagon – a polygon with 5 sides
Pens (pentagon) are held by your five fingers (five sides).
A famous Pentagon
The US Department of Defence team building is known as The Pentagon.
Although made as a spider’s web, there are three pentagons in this shape.
Regular pentagons have sides that are all the same length, irregular pentagons have two or more sides that are different lengths.
These are all pentagons but only the purple one in the middle is a regular pentagon, the others are all irregular pentagons.
Although this shape looks like a rectangle with a corner cut off, it is still a pentagon.
Pentagons can be convex or concave.