is radius, circumfrence, or diameter named after a king, queen, or prince?

None of them is named after a person.

They all come from Greek or Latin words.

No, they are from latin words which have meaning in geometry.

The terms "radius," "circumference," and "diameter" are not named after a king, queen, or prince. They are actually mathematical terms used to describe different attributes of a circle.

- Radius: The radius of a circle is the distance from the center of the circle to any point on its circumference. It is denoted by the letter "r" or sometimes "R".
- Circumference: The circumference is the distance around the outer edge of a circle. It is denoted by the letter "C".
- Diameter: The diameter is the distance across a circle passing through its center. It is equal to twice the radius. The letter "d" is often used to represent the diameter.

These terms have been used in mathematics for a very long time, and their origins are not attributed to any specific person or royalty. They are simply mathematical concepts that have been named based on their properties.