# Difference Between Circle and Sphere

When we talk about geometric figures, common sense often leads us to make some mistakes since we confuse one thing with the other; to the point of calling a thing by a name that does not correspond to it. Difference Between Circle and Sphere

Next we will see two figures that are often confused quite often, but that actually have many differences. It’s about the circle and the sphere. We will see what the differentiating characteristics are.

## CIRCLE Difference Between Circle and Sphere

The circle is a flat, round figure, whose limit (the circumference) is made up of points equidistant from a fixed point (the center). The circle is a two-dimensional figure and a plane. It is a simple form of Euclidean geometry, in which a set of all points in a plane are at a fixed distance from a given fixed point; known as the center.

A circle is a simple closed curve that divides the plane into two regions: one inside and one outside. Technically it is known as a disk. It is a curve that maintains a fixed distance, when it is drawn from the central point.

The study and development of this figure is in charge of one of the branches of Mathematics , Geometry, although it is also used in other fields such as calculus and astronomy. Some examples of circles in the real world are the wheels, plates, and the surface of a coin.

The terminology for a circle includes the following definitions:

**Center**: is the point equidistant from the points on the circle.**Radius**: a line segment that joins the center of the circle to any other point on it. It is the length of a segment of the circle, which is half the diameter.**Diameter**: it is a line segment whose ends meet in the circle and pass through the center of it. Join the two opposite points of a circle.**Circumference**: it is the length of a circuit along a circle.**Chord**: it is a segment of the line whose ends meet in the circle.**Tangent**: it is a straight line that touches the circle at a certain point.**Arc**: connected part of the circle.

## SPHERE

A sphere is a solid, round figure. On its surface, each of its points is equidistant from its center. It is a three-dimensional figure, which has volume. It resembles a ball.

The distance (r) is the radius of the sphere and the midpoint is the center of the sphere. The maximum distance that passes directly through the sphere, passes through its center and is therefore twice its radius; is the diameter.

Any plane that includes the center of a sphere divides it into two equal hemispheres. Archimedes created the formula for a sphere. The sphere is also defined as the surface formed by the rotation of a circle about any diameter. Any cross section through a sphere is a circle.

Just as in circles, in spheres all points are at a fixed distance from their center. Examples of spheres in nature are bubbles, planets, and drops of water.

**Basic properties of a sphere:**

- All the points of a sphere are at the same distance from the fixed point.
- The contours and flat sections of the spheres are circles.
- The spheres have a constant width and circumference.
- The spheres have no center on the surface.
- Spheres have a larger volume and the surface area is smaller.
- The spheres have a constant mean curvature.

**Key differences between circle and sphere**

- The circle is a figure with all the points at the same distance from its center. The sphere is a solid figure, completely round; with each point on its surface at an equal distance from its center.
- A circle is a two-dimensional figure, while a sphere is a three-dimensional figure.
- In a circle you can only calculate the area of its surface, while in a sphere you can calculate the area of the surface and also the volume.
- Examples of circles: armbands and tires. Sphere examples: tennis balls and planets.