What is a Polygon?
A polygon is a closed shape with straight sides. The sides of a polygon are line segments, and the place where two sides meet is called a vertex. Polygons are named by the number of sides they have. For example, a polygon with three sides is called a triangle, a polygon with four sides is called a quadrilateral, and so on.
Types of Polygons
There are several types of polygons based on the number of sides they have:
- Triangle: A polygon with three sides.
- Quadrilateral: A polygon with four sides.
- Pentagon: A polygon with five sides.
- Hexagon: A polygon with six sides.
- Heptagon (or Septagon): A polygon with seven sides.
- Octagon: A polygon with eight sides.
- Nonagon (or Enneagon): A polygon with nine sides.
- Decagon: A polygon with ten sides.
Properties of Polygons
Here are some important properties of polygons:
- Interior Angles: The sum of the interior angles of a polygon with n sides is given by the formula: (n - 2) * 180 degrees.
- Exterior Angles: The sum of the exterior angles of any polygon is always 360 degrees.
- Diagonals: A diagonal is a line segment that connects two non-adjacent vertices of a polygon. The number of diagonals in a polygon can be calculated using the formula: n(n-3)/2, where n is the number of sides.
Study Guide
When studying polygons, it's important to:
- Memorize the names and properties of common polygons, including triangles, quadrilaterals, pentagons, hexagons, and octagons.
- Understand the formulas for calculating interior and exterior angles, as well as the number of diagonals in a polygon.
- Practice identifying and drawing different types of polygons.
- Solve problems involving the properties of polygons, such as finding missing angles or sides.
Understanding polygons is essential in geometry and lays the foundation for more advanced concepts in mathematics.
[Polygon] Related Worksheets and Study Guides:
.◂Math Worksheets and Study Guides Eighth Grade. Three dimensional geometry/Measurement
Study Guide
Three dimensional geometry/Measurement 
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Three dimensional geometry/Measurement Worksheet/Answer key
Three dimensional geometry/Measurement Worksheet/Answer key
Three dimensional geometry/Measurement Worksheet/Answer key
Identify Solid Figures Worksheet/Answer key
Surface Area of Solid Figures Worksheet/Answer key
Surface Area and Volume Worksheet/Answer key
Volume of Solid Figures Worksheet/Answer key
Surface Area and Volume Worksheet/Answer key
Surface Area of Solid Figures Worksheet/Answer key
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Volume of Solid Figures
Worksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyThe resources above cover the following skills:
Geometry (NCTM)
Analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationships.
Precisely describe, classify, and understand relationships among types of two- and three-dimensional objects using their defining properties.
Use visualization, spatial reasoning, and geometric modeling to solve problems.
Use geometric models to represent and explain numerical and algebraic relationships.
Measurement (NCTM)
Apply appropriate techniques, tools, and formulas to determine measurements.
Select and apply techniques and tools to accurately find length, area, volume, and angle measures to appropriate levels of precision.
Develop strategies to determine the surface area and volume of selected prisms, pyramids, and cylinders.