Difference Between Circle and Sphere

Bookmark added to your notes.
View Notes
×

Let us draw a circle and a sphere in a piece of paper. What do we find? Both the shapes are the same because of their round format. Thus, many of us get confused in understanding them. Then what is the difference between a circle and a sphere? The basic sphere and circle difference is that the circle is 2-Dimensional, and a sphere is 3-Dimensional. Deriving from the basic difference we can get another difference that is one can compute the area of a circle, but for a sphere, we have to find its volume. 


Circle

A circle is considered as a type of line. A circular line consists of a set of points with a property that all the points present in that line are from a uniform distance from a fixed point on a plane. It consists of a closed-loop that divides plains into inner and outer sections. The various properties of a circle are centre, circumference, tangent, and chord. Radius is connected to its centre through the lines, and "r" depicts the length of the radius of that particular circular line.  Ellipse is a special case of a circle with a set of points with a constant sum of the distance between the two fixed points in a plane. These two fixed points are known as focus and centre, which are the same in the case of a circle. In the inner circle, one can find three sets of points that are not present in the same direction, which defines a triangle's edges. Some examples of the circle are disc, clock, etc.


Sphere

The sphere is a kind of line that contains various properties such as surface area, volume, and radius. It is an asymmetrical surface with one exterior only. The radius of a sphere links the midpoint to the outermost part. The diameter of the sphere starts from one edge to another, passing through its centre. The sphere consists of small circles and several hemispheres. A circle formed by the intersection of the sphere and the plane that passes through the centre of the space is known as the sphere's largest circle. In contrast, the other circles formed by the intersection of the plane and spear are known as small circles of that sphere. Greek mathematician Archimedes formulated the formula of the sphere. Examples of some spheres are marble, football, water droplets, etc.


There are Two Types of Sphere

  1. Solid sphere - Solid object, which is in the form of a sphere is known as a solid sphere. A solid sphere is filled with the same material from which it is made up of.

  2. Hollow sphere- When a solid sphere is cut from the middle and a big solid that is taken out of it leaving a spherical shell behind is called a hollow sphere. 

[Image will be Uploaded Soon]


Difference Between Sphere and Circle

Sl.No

Properties

Circle

Sphere

1

Dimension

A circle is a 2D figure

A sphere is a 3D object

2

Area formula

The area of a circle is 4πr2

The surface area of a sphere is 4πr2

3

Volume formula

A circle do not have a volume

The volume of a sphere is 4/3 πr³

4

Definition 

All the points of a circle are present at the same distance from its centre in a plane.

All the points in a sphere are equidistant at any axes from the centre.

5

Determination 

In the case of a circle, its area is determined

In the case of a sphere, its surface area and volume are determined.

6

Diameter formula

The diameter of a circle is 2r

The diameter of a sphere is 2r


Circumference formula

Circumference of a circle is 2πr

Sphere does not have a circumference

8

Equation

The equation of a circle 

(x - a)2 + (y - b)2 = r

The equation of a circle (x - a)2 + (y - b)2 + (z - c)2 = r2

9

Consideration 

The circle is considered as a figure

Sphere is considered as an object

FAQ (Frequently Asked Questions)

1. What Do You Mean By Hemisphere? How to Find Out the Volume of a Hemisphere?

In the word hemisphere, Hemi means half. So, half of a sphere is known as a hemisphere. A sphere is a set of three-dimensional points for the centre equidistant with all the points. Our earth comprises two hemispheres the northern and the southern hemispheres which are exactly divided into two shapes from the earth's midpoint. 

Hemisphere is the half of a sphere.

As we know that the volume of the sphere is 4/3 πr³

The volume of hemisphere = ½ x [4/3 πr³] = ⅔ πr³ 

Where r is the radius of the hemisphere. 

2. How to Derive the Formula of a Sphere?

As we know that the volume of a cylinder = πr²h

Volume of cylinder = volume of sphere + volume of cone

Volume of cylinder = 3 × volume of cone

πr²h = 3 × volume of cone

πr²h/3 = volume of cone

Volume of sphere = πr²h/3 + πr²h/3

The height of a cone = diameter of the sphere =2r

So, replace h =2r

The volume of the sphere will be = 2 × (2πr³/3)

Therefore, the volume of the sphere is 4/3πr³