What is a shape beginning with I?

Answer 1

2D Polygons

• Icosagon (20 sides)
• Icosikaihenagon (21 sides)
• Icosikaidigon (22 sides)
• Icosikaitrigon (23 sides)
• Icosikaitetragon (24 sides)
• Icosikaipentagon (25 sides)
• Icosikaihexagon (26 sides)
• Icosikaiheptagon (27 sides)
• Icosikaioctagon (28 sides)
• Icosikainoenneagon (29 sides)

3D Polyhedra

• Icosahedron (20 faces)
• 21-29 faces are same as the 2D names but with '-hedron' instead of '-gon' at the end.

Also:Isosceles Triangle / Trapezoid(Trapezium)