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Apothem Calculator

Apothem Formula:

\[ a = r \times \cos\left(\frac{180}{n}\right) \]

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1. What is the Apothem?

The apothem of a regular polygon is the distance from the center to the midpoint of one of its sides. It is an important measurement in geometry for calculating area and other properties of regular polygons.

2. How Does the Calculator Work?

The calculator uses the apothem formula:

\[ a = r \times \cos\left(\frac{180}{n}\right) \]

Where:

Explanation: The formula calculates the apothem using the radius and the central angle between vertices, which is 360/n degrees. The apothem is the adjacent side in the right triangle formed by the radius, apothem, and half of a side.

3. Importance of Apothem Calculation

Details: The apothem is crucial for calculating the area of regular polygons using the formula: Area = (1/2) × perimeter × apothem. It's also used in various geometric constructions and architectural designs.

4. Using the Calculator

Tips: Enter the radius (distance from center to vertex) and the number of sides (must be 3 or more). The calculator will compute the apothem using the trigonometric relationship.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between radius and apothem?
A: The radius extends from the center to a vertex, while the apothem extends from the center to the midpoint of a side.

Q2: Can this formula be used for irregular polygons?
A: No, this formula only works for regular polygons where all sides and angles are equal.

Q3: What's the minimum number of sides required?
A: The formula requires at least 3 sides (triangle) to form a polygon.

Q4: How is the apothem related to the side length?
A: For a regular polygon with side length s, the apothem can also be calculated as a = s/(2 × tan(180/n)).

Q5: Why use degrees instead of radians?
A: The formula uses degrees for the angle calculation as it's more intuitive for most users, though internally it's converted to radians for the cosine function.

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