octahedra, octahedron, octameter, octave, octachord
The prefix hepta- means seven. A heptagon is a polygon with seven sides. Other words that have this same prefix are: heptathlon, heptameter, herpetology, heptarch, heptads.
octagon, hexagon
Octagon, octane, octave, octavo
And octagon is an 8 sided triangle. A hexagon is a 6 side triangle. "Oct" is a prefix that means 8. "Hex" is a prefix that means 6.
Octogenarian, Octagon, Octuplet
Oct- is the prefix meaning eight. One of the most common words for this is octagon.
OctagonOctaneOctaveOctober
The prefix hendeca- (ΕΝΤΕΚΑ or ΕΝΔΕΚΑ / ένδεκα) is of Greek origin, so you probably won't find any other word in English with this prefix. Hendecahedron would be just alright, though.
a word for octa is octagonThe only word that I know that starts with octa is octagon.
An octagon is an eight-sided shape. The prefix is octa-, meaning eight. -Gon refers to the shape.
An octagon has 8 sides. The prefix "oct" means 8.
Words with the same prefix as decode:debriefdecomposedecreasedeductdefamedeflatedeformeddefusedefrauddegradedehydratedejecteddelousedemilitarizedemeritdemanddemarcationdenotedenouncedepressderailderangeddethronedetractdetaindevaluedevote