Regular Icosahedron Calculator

The regular icosahedron is one of the five Platonic solids. With 20 triangular faces, it has the most faces of any Platonic solid and is almost spherical.

Key Properties:

• 20 equilateral triangular faces
• 30 edges (all equal length)
• 12 vertices (each meets 5 triangles)
• Dual of the dodecahedron
• Dihedral angle: arccos(-√5/3) ≈ 138.19°

Applications:

The icosahedron is used in geodesic domes (Buckminster Fuller), 20-sided dice (d20 in games), virus capsid structures, and as a basis for many geometric constructions.