### Difference between Sphere and Circle

Circles and spheres both are circular shapes. As they are circular shapes, that’s why most of the people are confused about these shapes. Most of the people think that circles and spheres are the same shapes. They should know that there is a difference between the sphere and the circle. Its reason is that a circle is a two-dimensional figure. On the other hand, a sphere is a three-dimensional object. These two shapes are different in various ways. That’s why people have to face lots of problems to understand these two shapes. Here, we will discuss the difference between these two shapes.

## What is a Circle?

To form a circle, we have to move a point around the fixed point at the constant distance. In other words, we can say that a circle consists of a set of points in the plane. These points are at the fixed distance from the fixed point. A line that joins the centre of the circle with any point on the circle is the radius of the circle. In the same circle, all the radii have the same lengths. A line that joins two points on the circle is the chord. If a chord passes through the centre of the circle, it is the diameter of the circle. It means that to find the diameter of a circle, we have to join two radii. That’s why the length of the diameter of the circle is twice as that of its radius.

## What is the Sphere?

The three-dimensional form of a circle is known as a sphere. In a sphere, we have to see all the points on the surface of the sphere. These points are at an equal distance from the centre of the sphere. The width and girth of the sphere are constants. The volume of a sphere is greater. On the other hand, its surface area is smaller. The mean curvature of the sphere is also constant. Football is the best example of the sphere. There is no volume of the circle. On the other hand, we can measure the volume of a sphere by using a formula. In the case of a circle, we can determine its area. On the other hand, in the case of the sphere, we can determine surface area and volume.

## Difference between Sphere and Circle

A sphere and a circle are different in various ways. We will try to determine their differences one by one.

### 1. Difference between Definitions of Sphere and Circle

A circle is formed in the form of a closed curved line. All the points on this closed curved line are at the same distance. It means that the locus of a point at the fixed length from the fixed point forms a circle. The fixed point of the circle is its centre. On the other hand, if we join this fixed point with another point on the circle, it is the radius of the circle. Similarly, we can also form a sphere by drawing the locus of a point around the fixed point. Anyhow, it is a three-dimensional object in the space. To sum up, we can say that a circle is a round object in the plane. On the other hand, a sphere is a round object in the space.

### 2. Difference between Formulas of Sphere and Circle

To find the area of the circle, we use the formula πr2. On the other hand, to find the area of the sphere, we use the formula 4πr2. As we have discussed earlier that there is no volume of the circle. Anyhow, to find out the volume of the sphere, we use the formula 4/3πr3.

### 3. Dimensions

In the definitions of the circle and sphere, we have discussed that a circle is a round object in the plane. That’s why it is a two-dimensional figure. On the other hand, a sphere is a round object in the space. That’s why it is a three-dimensional object.

### 4. Diameter Formula

The diameters of both circles and spheres are the same. To find the diameters of the spheres and circles, we use the formula 2r. It means that if we join two points of the circle or sphere with a line that passes through the centre of the circle or sphere, it forms the diameter of the circle or sphere.

### 5. Circumference Formula

To find the circumference of a circle, we use the formula 2 π r. On the other hand, we can’t find the circumference of the sphere because it doesn’t have the circumference.

### 6. Equations

Both circles and spheres have the equations. There is also a difference between the equations of the circles and spheres. Their equations are given below;

Equation of the circle:

(x−a)2+(y−b)2= r2

Equation of the sphere is:

(x−h)2+(y−k)2+(z−l)2=r2

### 7. Examples

We can found examples of sphere and circles in almost all fields of life. Here, we will discuss real-life examples of circles and spheres. The real-life examples of circles are wheels and coins etc. On the other hand, the real-life examples of spheres are balls and planets etc.

### 8. What is it?

While understanding the difference between the two terms, you should also try to know the answer to this question. Its reason is that anyone can ask this question about these terms. If someone asks this question about the circle, you should answer that it is a figure. On the other hand, if someone asks the same question about the sphere, you should answer that it is an object.

### 9. Components of Sphere and Circle

In the case of the circle, we can find out the only area. On the other hand, in the case of the sphere, we can find the volume along with surface area.

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## Solved Examples Relevant to Sphere and Circle

After understanding the difference between these two circular shapes, we can easily solve examples relevant to these circular shapes.

1. What is the area of the circular shape whose radius is 7 cm?

Solution:

The radius of the circle = 7 cm

Formula to find the area of the circle = πr2

After putting the values in this formula, we will get the answer 153.86 sq. cm.

2. What is the area of a football whose radius is 4 cm?

Solution:

The radius of the football = 4 cm

Formula to find the area of the football = 4πr2

After putting values in this formula, we will get the answer 200.96 sq. cm.

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