data-ad-format="horizontal">



 

Icosahedron

Definition: An icosahedron is a regular polyhedron with 20 congruent equilateral triangular faces. It is one of the five Platonic solids.
Try this Click on the figure to stop rotation. Drag anywhere to rotate.

An icosahedron is a regular polyhedron that has 20 faces. All the faces are equilateral triangles and are all congruent, that is, all the same size. It is one of the five Platonic solids.

Faces 20. Each is an equilateral triangle
Edges 30
Vertices 12

Surface area

If s is the length of any edge, then each face has an area given by: Since there are 20 faces, when we multiply the above by 20 and simplify, we get the surface area of the whole object. As the formula:

Volume

If s is the length of any edge, then the volume enclosed by the icosahedron is given by the formula:
While you are here..

... I have a small favor to ask. Over the years we have used advertising to support the site so it can remain free for everyone. However, advertising revenue is falling and I have always hated the ads. So, would you go to Patreon and become a patron of the site? When we reach the goal I will remove all advertising from the site.

It only takes a minute and any amount would be greatly appreciated. Thank you for considering it!   – John Page

Become a patron of the site at   patreon.com/mathopenref

Related topics