What is the definition of the radius of a circle ?

The radius of a circle is the distance from its center to any point on the circumference. It is represented by the symbol 'r' in mathematical formulas.

How is the radius of a circle different from the diameter ?

The radius of a circle is half the length of the diameter. Mathematically, the diameter is equal to twice the radius (d = 2r).

Why is finding the radius important ?

Calculating the radius is essential for various mathematical and real-world applications, including geometry, physics, engineering, and design.

Formula

The formula to calculate the radius of a circle is:

$${\text{Radius}}_{}=\frac{{\text{circumference}}_{}}{{\text{2π}}_{}}$$

where

• Radius is the distance from the center to any point on the circumference
• Circumference is the distance from the center to any point on the circumference
• π is a mathematical constant approximately equal to 3.14159.

Examples: