Dodecagon Calculator

Find the area and perimeter of a regular dodecagon (12 sides).

Area 179.14
Perimeter 48

Formula: area = 3·(2 + √3)·s²

Step-by-step with your numbers:
1. Values used:
2. Side length = 4
3.
4. Area = 179.14
5. Perimeter = 48
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A regular dodecagon has twelve equal sides and interior angles of 150°.

How the Math Works

The area of a regular dodecagon is calculated using the formula Area = 3·(2 + √3)·s², where s is the side length. This formula arises from dividing the dodecagon into 12 congruent isosceles triangles, each with a central angle of 30°. By applying trigonometric relationships (specifically, the tangent of 15° for each triangle's height), the total area simplifies to the given expression. The perimeter is simply 12·s, as all sides are equal in a regular dodecagon. These formulas allow precise geometric calculations without complex measurements or approximations.

Practical Applications

This calculator is invaluable in fields requiring precise 12-sided geometry, such as architecture, engineering, and design. For instance, when creating a 12-sided decorative structure, garden planter, or architectural element, knowing the area helps estimate materials like tiles, paint, or fabric, while the perimeter aids in determining edging, fencing, or border requirements. It also supports 3D modeling for projects involving dodecahedrons, ensuring accurate surface area calculations for rendering or manufacturing. Users can quickly verify theoretical designs or adapt the formula for custom applications involving regular dodecagonal shapes.

Day-to-Day Use

In everyday scenarios, this calculator simplifies tasks involving 12-sided objects or spaces. For example, DIY enthusiasts crafting a 12-sided birdhouse or mosaic can use the formulas to measure wood, tiles, or paint accurately. Event planners might calculate space requirements for a 12-sided tent or seating arrangement. Even in games or puzzles, understanding dodecagon properties enhances spatial reasoning. By automating these calculations, the tool saves time and reduces errors, making it practical for hobbies, small projects, or educational purposes where geometric precision matters.

Worked example

Side 4 → area ≈ 179.14, perimeter 48.

FAQ

Is a clock face a dodecagon?

Conceptually yes — twelve equally spaced points form the vertices of a regular dodecagon.