Difference Between Circle and Sphere (with Table)

The closest thing which can remind us of a circle the earth, although not entirely a perfect one, and its’ area on which the human population is situated on, in this case, can be identified with a sphere.

Therefore, the geometry of circles and spheres has its broad application in every field of science, as an example – in geography, geology, and geodesy. Shapes that are spherical can be found at various places in nature, and because of human curiosity, there is a need for their description.

The difference between circle and sphere is that a circle is a 2-dimensional figure and a round object on a plane whereas, on the other hand, a sphere is a 3-dimensional figure and a round object in space.

Comparison Table Between Circle and Sphere

Parameter of ComparisonCircleSphere
DimensionsIt is a 2-dimensional figureIt is a 3-dimensional figure
Area formulaArea of a circle = πr2Surface Area of a Sphere = 4πr2
Diameter FormulaDiameter of a Circle = 2rDiameter of a Sphere = 2r  
Volume FormulaCircle does not have volume.Volume of a Sphere = 4/3πr2
Circumference FormulaCircumference of a Circle = 2πrSphere does not have the circumference

What is a Circle?

А circular line is a set of points in а plane with the property that every one of the points of that line is on an equal distance r of a fixed point of that plane called the centre of the circular line. Every line which connects the centre with some point of the circular line is termed a radius, and therefore the number r is the length of the radius of that circular line. in literature, the term circle, is perhaps, most frequently used. A circle is a special case of an ellipse.

Ellipse is often defined as a geometrical figure of the points within the plane with a constant sum of distances between two fixed points. in case of a circle, these two points (centre and focus) are identical. it’s known that every circle features a unique set of three points that don’t lie in a similar direction. These points define the triangle edges, and therefore the centre of the circumscribed circle of this triangle is within the cross-section of the bisection lines.

The distance from the centre to any of the three given points is the radius of the circle. another way to work out a circle through three points is to write down the general form equation of the circle, during a canonical (standard) or point-slope form, to incorporate the coordinates of the given points and to resolve the system. The area of a given circle with a radius r is equal to πr2.

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What is Sphere?

Space is often viewed as a group of points called elements of the space. A ball is a geometric body that’s a subset of space. It’s a group of points of a plane that are on a particular distance (length) from a fixed-point O. The point O is the centre of the sphere, and therefore the length that connects the centre with the furthest point of the sphere is termed a radius.

Diameter is the line that connects two most distant edge points (the longest straight line) of the sphere and passes through its centre. A circle formed by the intersection of the sphere and therefore the plane passing through the centre of the sphere is termed the circle of the sphere.

All other circles formed by the intersection of the plane and the sphere are called small circles of the sphere. Through every set of three points of the sphere, there’s just one circle that belongs to that.

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Main Differences Between Circle and Sphere

  1. A circle is a closed curved line. Each point on this curved line is on an equivalent distance from the focus (centre) of the circle. The locus of a point that’s at a fixed length from another point is known as a circle. The fixed point is a circle’s centre, and therefore the length between these two points its radius. Similarly, a sphere is additionally characterized as a locus of a point that’s at a constant distance from a fixed point – however in three-dimensional space. In simple terms – a circle is a round object in a plane, while a sphere is a round object in space.
  2. Circle, as a 2-dimensional figure has only an area – πr2. Sphere, on the opposite hand, as a 3-dimensional figure has an area – 4πr2 and a volume – 4/3πr2.
  3. Naturally, circle and sphere are figures that may be commonly found all around us. Although a real-world example of a circle is non-existent as there isn’t a zero-width object actually – some objects are often used to describe it – like wheels, cd’s, coins. samples of a sphere are maybe easier to seek out – tennis balls, planets, oranges, globes etc.
  4. A circle does not have a volume whereas the formula to determine the volume of the sphere is 4/3πr2.
  5. The formula to determine the circumference of a Circle = 2πr whereas a sphere does not have a circumference.

Conclusion

Circles and spheres have perfect symmetry around their centres. All the points of a circle, and therefore the furthest points of a sphere are on a fixed distance from the focus (centre). However, there are dissimilarities like that a circle is 2 dimensional, while a sphere is a three-dimensional object. the gap between the points that are most far away is termed a diameter (and is double the radius).

A circle has an area that may be calculated with the formula – πr2. A sphere along with an area features a volume that’s equal to 4/3πr2. Real-life samples of a circle can’t be found as a circle exists as a two-dimensional concept – it only got length and height and no width. Certain objects can resemble a circle – biscuit, pizza, tires. Sphere-like object examples are football, marbles, atoms, and so on.

References

  1. https://www.sciencedirect.com/science/article/abs/pii/S0262885698001607
  2. https://aip.scitation.org/doi/abs/10.1063/1.1673824?journalCode=jcp