What are shapes with sides called?

Let’s Talk Shapes: What Do You Call Those Things with Sides?

Geometry can seem intimidating, but at its heart, it’s just about understanding the world around us. And when it comes to basic shapes, those figures made up of straight lines, there’s one big category you should know: polygons. Ever wondered what to actually call them? Let’s break it down.

So, What’s a Polygon, Anyway?

Think of a closed-in figure made entirely of straight lines. That’s your polygon! Each line is a side (or edge, if you prefer), and where those sides meet? Those are the corners, or vertices. The word “polygon” comes from Greek – “poly” means “many,” and “gon” means “angle.” So, literally, it means “many angles”. Makes sense, right?

The Naming Game: It’s All About the Sides

Here’s where it gets interesting. We usually name polygons based on how many sides they have. It’s like a secret code using Greek prefixes and the suffix “-gon.” Ready for a quick rundown?

• Three sides? That’s a triangle, of course! Or, if you want to sound fancy, a trigon.
• Four sides? You’re probably thinking “square,” but the umbrella term is quadrilateral. Tetragon also works.
• Five sides? A pentagon! Think of the U.S. Department of Defense headquarters.
• Six sides? A hexagon. Bees love these for their honeycombs.
• Seven sides? This one’s a bit trickier: heptagon (or septagon).
• Eight sides? An octagon! Stop signs are a great example.
• Nine sides? Nonagon (or enneagon).
• Ten sides? Decagon.

You get the idea!

Beyond the Dozen: When Names Get a Little Crazy

Now, what happens when you get past 12 sides? Things get a little less common. A 13-sided shape is a triskaidecagon. Try saying that five times fast!

But honestly, most people just use the super-handy “n-gon” for anything with a bunch of sides. So, a shape with 41 sides? Easy – a 41-gon! If you are feeling particularly loquacious, you could call a 35-sided polygon a “triacontakaipentagon.”

Regular or Irregular? A Matter of Equality

Here’s another fun fact: polygons can be regular or irregular. A regular polygon is perfect – all sides are the same length, and all angles are the same. Think of a square or an equilateral triangle. Irregular polygons? They’re the rebels. Their sides and angles are all different.

Convex, Concave, and Complex: More Polygon Personalities

And there’s more! Polygons can also be convex (all angles pointing outwards), concave (at least one angle pointing inwards, making a “dent”), or even complex (where the sides cross each other).

Wrapping It Up

So, there you have it! Polygons, those many-sided shapes, come in all sorts of flavors. Knowing how to name them, and understanding the different types, is a great way to unlock a little bit of the magic of geometry. Now you can confidently identify and name shapes with sides, impressing your friends and maybe even understanding a little more about the world around you. Geometry: it’s not just for textbooks anymore!