๐ Math Dictionary
Radius
/RAY-dee-us/
Definition
The radius is the distance from the center of a circle to any point on its edge. It is exactly half the diameter. All radii (plural) of a circle are equal in length.
๐กExample
If a circle has a diameter of 10 cm, its radius is 10 รท 2 = 5 cm. The circumference formula C = 2ฯr uses the radius. Area formula A = ฯrยฒ also uses radius.
๐Used in Grades
Grades 4-10KS2 to GCSEร
rskurs 4-9
๐Related Terms
๐Learn More
Practice with Radius
Generate practice problems that use this concept.
Create Ready-to-Use Math Test (PDF)Ready in a few minutes. No editing needed.