Decagon

A decagon is a polygon with 10 sides and 10 angles. The sum of the interior angles of a decagon is 1440 degrees. Each interior angle of a regular decagon measures 144 degrees.

Properties of a Decagon:

1. A decagon has 10 sides.
2. A decagon has 10 angles.
3. The sum of the interior angles of a decagon is 1440 degrees.
4. Each interior angle of a regular decagon measures 144 degrees.
5. A decagon can be regular or irregular.

Formulas for Decagon:

1. Sum of interior angles = (n-2) * 180 degrees, where n is the number of sides
2. Each interior angle of a regular decagon = Sum of interior angles / number of sides

Example Problem:

Calculate the measure of each interior angle of a regular decagon.

Given: Number of sides (n) = 10

Using the formula, each interior angle of a regular decagon = (Sum of interior angles) / (Number of sides) = 1440 / 10 = 144 degrees

Study Guide:

• Understand the definition of a decagon as a polygon with 10 sides and 10 angles.
• Memorize the formula for finding the sum of the interior angles of a decagon.
• Practice finding the measure of each interior angle of a regular decagon using the formula.
• Identify and differentiate between regular and irregular decagons.

With this study guide, you can now confidently understand and work with the properties and formulas related to decagons!