I. Radius: A straight line extending from the center of a circle to the boundary of the circle, or from the center of a sphere to the surface of the sphere.
II. Diameter: A straight line passing from side to side through the center of a circle or sphere.
III. Circumference: The distance around the outside of a circle.
IV. Area: The amount of space inside the boundary of a two-dimensional shape, like a circle or a square.
V. Surface Area: The total area that covers the surface of a three-dimensional object, such as a cube or cylinder.
VI. Volume: The amount of space occupied by a three-dimensional object, like a cube, sphere, or cylinder.
