What does the radius of a sphere join?

any two points on the sphere and does not contain the center

any two points on the sphere and contains the center <~my choice

any two points on the sphere

the center and a point on the sphere

I think you'd better consider a circle. What does a radius of a circle join?

Care to revise your answer?

The center and a point on the sphere.

The correct answer is: the radius of a sphere joins the center of the sphere and a point on the sphere.

Explanation:

To understand this, we need to know what a sphere is. A sphere is a three-dimensional object that is perfectly round in shape, similar to a ball. It is made up of all the points in space that are equidistant from the center.

The radius of a sphere refers to the distance between the center of the sphere and any point on its surface. It is like a line segment that starts at the center and extends to the outer edge of the sphere.

When we talk about the radius joining something, it means connecting or linking two specific points. In the case of a sphere, the radius connects the center of the sphere to any point on its surface.

However, it's crucial to note that the radius does not connect any two random points on the sphere. It specifically connects the center of the sphere to a point on its surface. The radius does not pass through the center; it stops at the center.

So, the correct answer is that the radius of a sphere joins the center and a point on the sphere.