great circle
If your question is " What is the shape of a sphere's tangent?" , then the answer is : a plane. A plane basically touches the sphere at only one point and hence , it should be a plane. It cannot be a straight line , as a straight line is a tangent for 2D objects,( ie.) a circle.
A Circle.
A circle, which could degenerate to a point.
We're having a hard time making out the dark grey area from here. But the intersection of a plane and a sphere is always a circle.
It will be a point if the plane is tangent to the sphere.
The intersection of a sphere with a plane is a point, or a circle.
great circle
A circle~
If your question is " What is the shape of a sphere's tangent?" , then the answer is : a plane. A plane basically touches the sphere at only one point and hence , it should be a plane. It cannot be a straight line , as a straight line is a tangent for 2D objects,( ie.) a circle.
A Circle.
A circle, which could degenerate to a point.
We're having a hard time making out the dark grey area from here. But the intersection of a plane and a sphere is always a circle.
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.
The dark area is so dark that I'm unable to see it from here. But I do know that in general, the intersection of a plane and a sphere is a circle.
tangent
Not necessarily. A plane dissecting a sphere would create a circle in that plane. so in order for the "line" to be both on the plane and the sphere the line would have to be a curve or segment of a circle.