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.
Video Examples: How to Find a Radius Between Two Points
Solved Example on Radius
Ques: Find the radius of a circle with area 153.86 square inches. Take π = 3.14
- A. 8
- B. 7
- C. 6
- D. 5
Correct answer: B
- Step 1: Area of a circle of radius r = π r2 [Original equation.]
- Step 2: 153.86 = 3.14 r2 [Substitute values.]
- Step 3: [Divide each side by 3.14.]
- Step 4: 49 = r2 [Simplify.]
- Step 5: [ Evaluate square root on both sides.]
- Step 6: r = 7 [Ignore the negative value.]