Sphere

Go to Surface Area or Volume.

Sphere Facts

Notice these interesting things:

Sphere Radius

  • It is perfectly symmetrical
  • All points on the surface are the
    same distance "r" from the center
  • It has no edges or
    vertices (corners)
  • It has one surface
    (not a "face" as it isn't flat)
  • It is not a polyhedron
Glass Sphere
Glass Sphere.
Balls and marbles are shaped like spheres.

You can spin or drag this sphere:

images/poly-gl.js?mode=sphere
images/balloon.js

Largest Volume for Smallest Surface

Of all the shapes, a sphere has the smallest surface area for a volume. Or put another way it can contain the greatest volume for a fixed surface area.

Example: if you blow up a balloon it naturally forms a sphere because it is trying to hold as much air as possible with as small a surface as possible. Press the Play button to see.

 

bubble

In Nature

The sphere appears in nature when a surface wants to be as small as possible. Examples include bubbles and water drops. Can you think of more?


Volume and Surface Area

Sphere Radius

Surface Area = 4 × π × r2

Example: r = 5

Surface Area = 4 × π × r2
 = 4 × π × 52
 = 4 × π × 25
 = 100 π
 ≈ 314

 

Volume = (4/3) × π × r3

Example: r = 5

Volume = (4/3) × π × r3
  = (4/3) × π × 53
 = (4/3) × π × 125
 ≈ 524

Try dragging point "A":

Also see Volume and Area of a Sphere Calculator

 

Spheroid

The Earth

The Planet Earth, our home, is nearly a sphere, except that it is squashed a little at the poles.

Earth is a Spheroid
So it is technically a spheroid, but a very mild version of one.

Here is a more extreme spheroid:

Spheroid

 

sphere crystal

Hemisphere

A hemisphere is an exact half of a sphere.

Other Cool Spheres

sphere crystal

marble

Jade Sphere Light Sphere
Dark Sphere Brass Sphere

 

865,866,867,868, 1831, 1832, 3383, 3384, 3385, 3386