What does octagon mean?
Word: Octagon
Part of Speech: Noun
Meaning: Octagon means a flat shape with eight straight sides and eight angles.
How do you spell octagon?
Syllables: oc - ta - gon
Tricky part: After oct comes an a, not an o. Students mix it up with octopus and write octogon.
Watch out for: octogon, octegon
Memory tip: Octopus has eight arms with an o; the shape has eight sides with an a. Say oc-TA-gon and stress the a in your head.
Octagon in a sentence
Example 1: The red STOP sign on the road is shaped like an octagon.
Example 2: Our maths teacher asked us to draw an octagon and count its diagonals.
Example 3: The old fort has a tower built in the shape of an octagon.
Fun Fact
The inside angles of a regular octagon are each 135 degrees, and together they add up to 1080 degrees.
Practise the CREST Way
Word Champ
In which option are the given words arranged in alphabetical order?
1. octopus 2. octagon 3. octave
a) 132
b) 321
c) 231
d) 213
Show answer
c) 231. Octag comes before octav because g comes before v, and both come before octo.
Spell Spies
Choose the pair which has a spelling error:
a) square : 4 sides
b) octagan : 8 sides
c) triangle : 3 sides
d) hexagon : 6 sides
Show answer
b) octagan : 8 sides. The shape names end in -gon, as in hexagon and polygon, so octagan is wrong.
Jumble Tumble
What is the meaning of the word that can be formed from the given letters?
gotcaon
a) a flat shape with six straight sides
b) a sea creature with eight long arms
c) a group of eight singers or players
d) a flat shape with eight straight sides
Show answer
d) a flat shape with eight straight sides. The seven letters make only the shape word; the sea creature needs a p and the group of eight is an octet.
Sound Check
In which word is 'oc' pronounced differently?
a) octopus
b) ocean
c) octagon
d) doctor
Show answer
b) ocean. In ocean, oc is said like the o of go followed by sh; in the others it is the short o of hot and a k.
Multiple Choice Questions
1. If you join one corner of an octagon to every other corner, how many triangles do you make?
a) 8
b) 6
c) 5
d) 7
Show answer
b) 6
2. A regular octagon has sides that are all ___.
a) of different lengths
b) the same length
c) slightly curved
d) longer at the bottom
Show answer
b) the same length
