noun
- a three-dimensional geometric shape with twenty flat triangular faces
Usage: geometry
Examples
- The icosahedron is one of the five Platonic solids.
- Each face of an icosahedron is an equilateral triangle.
- The geometry teacher showed us how to construct an icosahedron from paper.
- An icosahedron has 12 vertices and 30 edges.
- The soccer ball’s design is based on a truncated icosahedron.
- Students struggled to visualize the complex icosahedron shape.