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A sphere is a 3-dimensional surface, and if you look at a circle, it has no sides. Spheres are similar; you can think of them as having infinitely small surface areas.

Additionally, spheres, circles, and any other shape of that nature have a different way of computing surface area or volume. It is because they do not have edges or vertices for easier computation.

## History

**What is Hellenistic Astrology?**

The existence of spheres goes as far back as the 3rd century B.C. It was when Hellenistic Astronomy figured out that the earth has a spherical shape.

They even roughly calculated the circumference of the earth. This information carried on up until the middle ages.

In terms of sculpture, the first spheres were found in Costa Rica. It is thought to be made around 800 A.D. to 1500 A.D by native ancestral tribes.

These were made from a rock called granodiorite. Over 300 spheres from this era have been identified.

## Surface Area

To get the surface area of the sphere, you use the formula A = 4 x Pi x r^{2}. The ‘r’ stands for the radius, which is the distance from the sphere’s center up until the sphere’s edge.

For example, a sphere with a radius of 5cm will have a surface area of (A = 4 x 3.14 x 5^{2}). If you calculate that, you will get a surface area of 314.16cm^{2}.

## Volume

**Volume of a Sphere | MathHelp.com**

For the volume of a sphere, a different formula is used. You can use the formula V = 4/3 x Pi x r^{3}. The ‘r’ still stands for the radius of the sphere.

When using the same example and giving the sphere a radius of 5cm, the volume would be (V = 4/3 x Pi x 5^{3}). So, if calculated, it gives a volume of 523.6cm^{3}.

## Frequently Asked Questions

### Are all points in a sphere’s surface the same?

It depends on how you would compare them. In terms of distance to the sphere’s center, they are all the same.

### But why is a sphere’s surface area four times its shadow?

### Is the Earth really a sphere?

When seen with the naked eye from space, the earth will appear to be a perfect sphere. However, this isn’t necessarily the case.

The earth is always in motion, it orbits around the sun, and it rotates at very high speeds. These motions can alter the shape of the earth from a sphere to an ellipsoid.

For those who don’t know what an ellipsoid looks like, imagine a slightly flattened sphere. Exactly calculating the earth’s surface area and volume might require different formulas.

### What is an equator?

The Equator is the diameter that is in the middle of the north and south poles. It segments the earth into the Northern and Southern hemispheres.

In terms of the earth being an ellipsoid, the equator is where the earth is the widest.