Geometry

Question Analysis

This question is about the basic property of a regular polygon, specifically focusing on the number of sides of a nonagon. It tests the understanding of polygon nomenclature.

 

Key Concept Explanation

Regular Polygons: These are two - dimensional closed figures with straight sides, where all sides and angles are equal. The naming of regular polygons is often based on the number of their sides, with many names derived from Greek or Latin roots.

 

Step - by - Step Solution

The term "nonagon" comes from the Latin word "nonus" meaning "ninth" and the Greek word "gonia" meaning "angle". So, a nonagon is a polygon with 9 sides.

 

Option Analysis

A.8: A polygon with 8 sides is called an octagon, not a nonagon, so this option is incorrect.

B.9: This is the correct answer. As explained above, a nonagon has 9 sides.

C.10: A polygon with 10 sides is a decagon, not a nonagon, so this option is wrong.

D.12: A polygon with 12 sides is a dodecagon, not a nonagon, so this option is incorrect.

 

Common Mistakes

Confusing the names and side numbers of different polygons, especially those with similar - so...