Radii are the plural form of radius, which refers to the distance from the center of a circle or sphere to any point on its circumference or surface.
Think of radii as spokes on a bicycle wheel. Just like each spoke connects the center of the wheel to a specific point on its rim, radii connect the center of a circle or sphere to different points on its circumference or surface.
Diameter: The diameter is a line segment that passes through the center of a circle or sphere and has both endpoints on its circumference or surface.
Circumference: The circumference is the distance around the outer edge of a circle.
Surface Area: Surface area refers to the total area covering all sides (including curved surfaces) of an object, such as a sphere.
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