# Is a circle a sphere?

A circle is two dimensional whereas a sphere is three dimensional, so they are different things. Any two dimensional section or slice of a sphere is a circle, however.

### What is the difference between spherical and circle?

A sphere is a three dimentional shape, a circle is a two dimentional shape. You can't pick up a circle, it can only be drawn. In differential geometry, a one dimensional sphere is a point, a two dimensional sphere is a circle and a three dimensional sphere is what we call a "sphere", there is no limit to the number of dimensions a sphere can have.

### What is a great cicle?

Much bigger and better than a regular circle... But seriously, a great circle on a sphere is a circle that runs along the surface of that sphere and cuts it into two equal halves. It is the largest circle that can be drawn on a given sphere. The center of any great circle is the center of the sphere.

### What is the largest circle that can be drawn around a sphere such as a globe?

That's called a "great circle" of the sphere. -- It's any circle whose center is at the center of the sphere. -- Its diameter is equal to the diameter of the sphere. -- Its area is equal to 1/4 the surface area of the sphere. -- The shortest distance between any two points on the sphere is along the piece of the great circle on which they lie. (There's only one, unless the two points…

### Why is the great circle important?

A great circle is a circle on the surface of a sphere whose center is at the center of the sphere. The shortest distance between two points on the surface of a sphere (like the Earth for example) is the piece of the great circle that joins them. If you're flying, then that's the route you want to follow.

### What is a great circle in spherical geometry?

The great circle is the intersection of a sphere and any plane passing through its centre. Given two distinct points on the surface of a sphere, those two points and the centre of the sphere define a plane. [If one of the points is at the antipodes of the other, an infinite number of planes are defined.] The great circle is the circle formed when that plane meets the surface of the sphere.