Radius
Definition of Radius
- Radius is the distance from the center of a circle or a sphere to any point on the circle or a sphere.
- In other words, radius is a line segment joining the center of a circle with any point on the circle.
Examples of Radius
is a radius of the circle shown.
Solved Example on Radius
Find the radius of a circle with area 153.86 square inches. 
Choices:
A. 8
B. 7
C. 6
D. 5
Correct answer: C
Solution:
Step 1: Area of a circle of radius
[Original equation.]
Step 2: 153.86 = 
[Substitute values.]
Step 3: 
[Divide each side by 3.14.]
Step 4: 
[Simplify.]
Step 5: 
[Evaluate square root on both sides.]
Step 6: r = 7 [Ignore the negative value.]
Related Terms for Radius
- Line Segment
- Center
- Circle
- Sphere
Additional Links for Radius
