{{ item.displayTitle }}

No history yet!

Student

Teacher

{{ item.displayTitle }}

{{ item.subject.displayTitle }}

{{ searchError }}

{{ courseTrack.displayTitle }} {{ statistics.percent }}% Sign in to view progress

{{ printedBook.courseTrack.name }} {{ printedBook.name }} A radius of a circle is a segment whose endpoints are the center of the circle and a point on the circle. By definition of circle, all radii are congruent.

On the other hand, the phrase
Furthermore, the radius of a circle is exactly half the length of the circle's diameter.

$r = \dfrac{d}{2}$