What has the same prefix as heptagon?

The prefix "hept-" means "seven". So, any word with the prefix "hept-" will be related to the number seven. Here are a few examples:

* Heptathlon: A track and field event with seven disciplines.

* Heptameter: A line of poetry with seven metrical feet.

* Heptavalent: Having a valency of seven.

* Heptahedron: A polyhedron with seven faces.