Radius

/ˈreɪdiəs/

Meaning & Definition

noun

A straight line from the center to the circumference of a circle or sphere.

The radius of the circle is 5 centimeters.

The length of such a line.

To find the area of the circle, you need to calculate the radius.

A circle or sphere having a specified radius.

The design included a radius of 10 meters around the central fountain.

verb

To extend or measure out in radius.

They decided to radius the search area to maintain efficiency.

Latin 'radius' meaning 'spoke of a wheel' or 'ray of light'.

radius of action

The area in which influence or activity occurs.

within a radius

In proximity to a specified distance.

radius of influence

The area in which one has power or ability to affect.

diameter

A straight line passing from side to side through the center of a figure, especially a circle.

circumference

The enclosing boundary of a curved geometric figure, especially a circle.

arc

A part of the circumference of a circle.