Here's a breakdown:
* Circle: In a circle, the diameter is the longest possible chord (a line segment connecting two points on the circle).
* Sphere: In a sphere, the diameter is the longest possible line segment passing through the center.
Key points:
* The diameter is always twice the radius of a circle or sphere.
* The diameter is a useful measurement for determining the size and area of circular shapes.
Examples:
* The diameter of a pizza is the distance across the pizza through the center.
* The diameter of a basketball is the distance across the basketball through the center.
Let me know if you have any other questions!