What is a straight line on a sphere called?

Lines in Euclidean space and great circles on spheres are examples of what’s called geodesics in differential geometry.

What is a straight line on a cone?

Either half of a double cone on one side of the apex is called a nappe. The axis of a cone is the straight line (if any), passing through the apex, about which the base (and the whole cone) has a circular symmetry.

Do cylinders have straight lines?

Cylinder, in geometry, surface of revolution that is traced by a straight line (the generatrix) that always moves parallel to itself or some fixed line or direction (the axis). The path, to be definite, is directed along a curve (the directrix), along which the line always glides.

Are there parallel lines on a sphere?

If there is a line and a point not on the line, then there exists exactly one line through the point that is parallel to the given line. There are no parallel lines in spherical geometry.

Can a line intersect itself on a sphere?

A line can intersect a sphere at one point in which case it is called a tangent. It can not intersect the sphere at all or it can intersect the sphere at two points, the entry and exit points.

Does a cone have parallel lines?

The lines in the definitions are called generating lines of the cylinder or the cone. The intersection of the cylinder or cone with a plane parallel to the plane of c is called an equatorial circle (for the cone, one special case is does not give a circle – the parallel plane through P).

Can you draw a straight line on a sphere?

On the surface of a sphere, however, there are no straight lines. The shortest path between two points on the surface of a sphere is given by the arc of the great circle passing through the two points.

Does a sphere have a curved face?

A sphere has no edges and therefore no corners. It has one curved face that goes all the way around.

What happens to parallel lines on a sphere?

In spherical geometry Parallel lines DO NOT EXIST. In Euclidean geometry a postulate exists stating that through a point, there exists only 1 parallel to a given line.

What is a Lune on a sphere?

In spherical geometry, a spherical lune (or biangle) is an area on a sphere bounded by two half great circles which meet at antipodal points. The word “lune” derives from luna, the Latin word for Moon.

At what points does this line intersect the sphere?

Lines of constant phi are often referred to as lines of latitude, for example the equator is at phi = 0. A line can intersect a sphere at one point in which case it is called a tangent. It can not intersect the sphere at all or it can intersect the sphere at two points, the entry and exit points.

What is a parallel cross section?

Horizontal or Parallel Cross Section In parallel cross-section, a plane cuts the solid shape in the horizontal direction (i.e., parallel to the base) such that it creates the parallel cross-section.

Which is the longest straight line through the sphere?

The longest straight line segment through the ball, connecting two points of the sphere, passes through the center and its length is thus twice the radius; it is a diameter of both the sphere and its ball.

Why are there no straight lines in spherical geometry?

Lines in spherical geometry are more subtle. Since the surface is curved, there are no straight lines on it, in the usual sense of the word straight. Because of this, we use the word geodesic instead of line when talking about spherical geometry: A geodesic in non-Euclidean geometry plays the role that a straight line plays in Euclidean geometry.

How is the diameter of a sphere determined?

You will find a point equidistant from any point on the surface of a sphere. The longest straight line that passes through the center of the sphere is called the diameter of the sphere. It is twice the length of the radius of the sphere.

What do you call the radius of a sphere?

A perfectly symmetrical 3 – Dimensional circular shaped object is a Sphere. The line that connects from the center to the boundary is called radius of the square. You will find a point equidistant from any point on the surface of a sphere. The longest straight line that passes through the center of the sphere is called the diameter of the sphere.