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## IPA:

The distance from the center of a circle or sphere to any point on its circumference or surface.
"The geologist analyzed the radius of the impact crater to assess its size and force."

It represents a straight line segment that connects the center of the circular shape or sphere to its outer edge or boundary. The radius is half the length of the diameter, making it one of the fundamental measurements in geometry. It plays a crucial role in determining the size, proportions, and characteristics of circular objects. The radius helps define the extent and reach of a circle, providing important information about its dimensions, such as circumference, area, or volume. Beyond circles, the term can also apply to other spherical or curved objects, such as spheres or cylinders, where it represents the distance from the center to the surface. Understanding the radius is essential for analyzing and comprehending the properties, relationships, and calculations associated with circular or symmetrical objects in various fields, including mathematics, physics, and engineering.

1. The carpenter measured the radius of the table leg before shaping it.
2. The radius of the planet determined its gravitational pull.
3. The cyclist carefully adjusted the radius of the bike's wheels for optimal performance.
4. The botanist studied the radius of tree rings to estimate the tree's age.
5. The architect calculated the radius of the arch to ensure structural stability.
6. The engineer determined the radius of the pipeline for efficient fluid flow.

## History and etymology of radius

The noun 'radius' can be traced back to Latin origins. It is derived from the Latin word 'radius,' which had multiple meanings, including a rod, spoke of a wheel, or a ray. In the context of geometry, the term 'radius' was used to refer to the spoke of a wheel, and it eventually came to represent the distance from the center of a circle or sphere to any point on its circumference or surface. This shift in meaning from a physical object like a spoke to a geometric concept reflects the evolution of language and how words adapt to describe abstract ideas. Etymologically, 'radius' embodies the idea of a spoke extending from a central point and, by extension, the distance from the center to the outer boundary of a circular or spherical object, as it is understood in geometry today.

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## Further usage examples of radius

1. The mathematician used the radius to calculate the area of the circle.
2. The surgeon measured the radius of the patient's bone to select the appropriate implant.
3. The astronomer estimated the radius of the star based on its brightness and temperature.
4. The artist used a compass to draw circles of different radii on the canvas.
5. The mechanic checked the radius of the car's tire to ensure it was within the recommended range.
6. The radius of the circle is half of its diameter.
8. She measured the radius of the sphere with precision.
9. The radius of the hurricane expanded rapidly.
10. Calculate the radius to find the circle's area.
11. The radius of a circle can be used to find its circumference.
12. The car's turning radius was surprisingly tight.
13. Astronomers study celestial bodies' radii to understand their size.
14. Engineers measured the bridge's arch radius carefully.
15. The planet's orbit has a variable radius.
16. The radius of a bubble determines its size.
17. The radius of a cylinder can be calculated from its volume.
18. He sketched a circle with a large radius.
19. The radius of the well was deeper than expected.
20. The sphere's radius affects its volume.
21. Calculate the radius of the cone to find its slant height.
22. The radius of a crater can reveal its age.
23. The circle's radius dictates its circumference.
25. He estimated the radius of the pizza to share it equally.

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