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### Unit 16: Lesson 3

Properties of shapes

# Polygons review

Review the term polygon and name polygons with up to 8 sides.  Then, try some practice problems.

## What is a polygon?

A polygon is a closed figure with at least 3 straight sides.

## Practice set 1

Problem 1A
Is the following figure a polygon?

## Identifying polygons

Polygons can be named by their number of sides.
Number of sidesName
3Triangle
5Pentagon
6Hexagon
7Heptagon
8Octagon

### Practice set 2

Problem 2A
Which of these shapes are quadrilaterals?

Want to try more problems like this? Check out this exercise

## Want to join the conversation?

• What is the difference Between a Circle, Ellipse And an oval .
• Well, a circle is identical all around it, an ellipse changes due to it's diameter, and an oval, similar to an ellipse, is never identical all around. Hope this helps!
• What's a polygon
• A polygon is made of any three straight sides with the lines all connected to each other, as well as not overlapping and meeting at the ends of the lines.
• Actually does anyone know the name of a 20-sided shape?
• A 20 - sided shape is called a icosagon. To learn about other shapes with a lot of sides go to:
https://sngweb.com/education/formula/geometry/polygon_name.html
• Is Nonagon Belong In A Polygon?
• Yes a nonagon is a polygon, one with nine sides and angles.
• 3 dimensional octagon is called a octahedron
• A three dimensional octagon is a octagonal prism. An octahedron is a square pyramid stacked on top of another one, and it has 8 sides.
• what would a ten sided shape be called?
• Decagon. In geometry, a decagon is a ten-sided polygon or 10-gon