In geometry, a pentagon is any five-sided polygon or 5-gon. The sum of the internal angles in a simple pentagon is 540°.
Pentagonal cross-section of okra.
Morning glories, like many other flowers, have a pentagonal shape.
Perigone tube of Rafflesia flower.
The gynoecium of an apple contains five carpels, arranged in a five-pointed star
In geometry, a polygon is a plane figure made up of line segments connected to form a closed polygonal chain.
Historical image of polygons (1699)
The Giant's Causeway, in Northern Ireland