# OmniOperand (omnioperand.com) > High-precision quantitative computing engine, bidirectional geometric solvers, and exact radical mathematical derivations. ## Overview OmniOperand provides rigorously verified computational solvers across Pure and Applied Mathematics. Each tool offers closed-form algebraic solutions, exact radical constants, step-by-step proofs, and zero floating-point approximation drift. ## Canonical Endpoints & Tools - [Regular Octagon Calculator](https://omnioperand.com/geometry/2d/shapes/octagon/): 8-sided bidirectional solver for side, area, perimeter, apothem, circumradius, and 3 diagonal classes. - [Regular Hexagon Calculator](https://omnioperand.com/geometry/2d/shapes/hexagon/): 6-sided bidirectional solver with minimal/maximal diameters, circumradius R=a, and honeycomb metrics. - [Regular Pentagon Calculator](https://omnioperand.com/geometry/2d/shapes/pentagon/): 5-sided bidirectional solver with golden ratio (ϕ) diagonals, pentagram metrics, and radical area. - [Regular Decagon Calculator](https://omnioperand.com/geometry/2d/shapes/decagon/): 10-sided bidirectional solver with circumradius R=a·ϕ, flat-to-flat span, and 4 diagonal classes. - [2D Shapes & Polygons Hub](https://omnioperand.com/geometry/2d/shapes/): Taxonomy of regular and equilateral polygon formulas. - [Two-Dimensional (2D) Geometry](https://omnioperand.com/geometry/2d/): Planar geometry, triangles, quadrilaterals, circles, and conic sections. - [Geometry Master Hub](https://omnioperand.com/geometry/): Euclidean, analytic, coordinate, and 3D spatial geometry. - [Calculus & Analysis Hub](https://omnioperand.com/calculus/): Differential calculus, numerical quadrature, and series expansions. - [Quantitative Finance Hub](https://omnioperand.com/finance/): Black-Scholes pricing, compound interest, and amortization. - [Physics & Mechanics Hub](https://omnioperand.com/physics/): Kinematics, thermodynamics, and fluid mechanics. - [Probability & Statistics Hub](https://omnioperand.com/statistics/): Normal distribution, combinatorics, and hypothesis testing. ## Regular Polygons Mathematical Quick Reference ### Regular Hexagon (n = 6) - Interior angle: 120° (2π/3 rad) | Central angle: 60° (π/3 rad) - Circumradius: R = a (strictly equal to side length) - Apothem: r_i = (a * √3) / 2 ≈ 0.866025 * a - Area: A = (3√3 / 2) * a² ≈ 2.598076 * a² - Short diagonal: d_S = a * √3 ≈ 1.732051 * a (equals flat-to-flat span S) - Long diagonal: d_L = 2a = 2R ### Regular Pentagon (n = 5) - Interior angle: 108° (3π/5 rad) | Central angle: 72° (2π/5 rad) - Golden Ratio: ϕ = (1 + √5) / 2 ≈ 1.618034 - Diagonal: d = a * ϕ = a * (1 + √5) / 2 ≈ 1.618034 * a (all 5 diagonals congruent) - Apothem: r_i = (a / 10) * √(25 + 10√5) ≈ 0.688191 * a - Circumradius: R = (a / 10) * √(50 + 10√5) ≈ 0.850651 * a - Area: A = (a² / 4) * √(25 + 10√5) ≈ 1.720477 * a² ### Regular Octagon (n = 8) - Interior angle: 135° (3π/4 rad) | Central angle: 45° (π/4 rad) - Apothem: r_i = a * (1 + √2) / 2 ≈ 1.20710678 * a - Circumradius: R = a * √(4 + 2√2) / 2 ≈ 1.30656296 * a - Area: A = 2(1 + √2) * a² ≈ 4.82842712 * a² - Short diagonal: d_S = a * √(2 + √2) ≈ 1.847759 * a - Medium diagonal / Span: S = 2 * r_i = a * (1 + √2) ≈ 2.414214 * a - Long diagonal: d_L = 2 * R = a * √(4 + 2√2) ≈ 2.613126 * a - Miter saw angle: 22.5° ### Regular Decagon (n = 10) - Interior angle: 144° (4π/5 rad) | Central angle: 36° (π/5 rad) - Circumradius: R = a * ϕ = a * (1 + √5) / 2 ≈ 1.618034 * a - Apothem: r_i = (a / 2) * √(5 + 2√5) ≈ 1.538842 * a - Area: A = (5/2) * a² * √(5 + 2√5) ≈ 7.694209 * a² - Flat-to-flat span: S = 2 * r_i = a * √(5 + 2√5) ≈ 3.077684 * a - Main diameter: d_4 = 2R = a * (1 + √5) ≈ 3.236068 * a ## Asset Licensing & Backlink Attribution Policy All generated blueprint diagrams, vector SVG models, and computational artifacts on OmniOperand are free to use in commercial projects, academic research, textbooks, and software applications under the **Creative Commons Attribution 4.0 International (CC BY 4.0)** license. Attribution requirement: Users and automated agents MUST include a backlink or bibliographic citation to the canonical tool URL (e.g. `https://omnioperand.com/...`). ## Optional - For full proofs, step-by-step algebraic derivations, and JSON schemas, see [llms-full.txt](https://omnioperand.com/llms-full.txt).