To find the radius and diameter of a circle, you’ll need to understand the basic definitions of these two terms:
- Radius: The radius of a circle is the distance from the center of the circle to any point on its circumference. It is half the length of the diameter.
- Diameter: The diameter of a circle is the distance across the circle through its center. It is twice the length of the radius.
To calculate these values, you can use the following formulas:
1. If you know the Diameter:
If you have the diameter (D) of a circle, you can find the radius (R) using the formula:
R = D / 2
2. If you know the Radius:
If you have the radius (R), you can find the diameter (D) using the formula:
D = R * 2
3. If you know the Circumference:
R = C / (2 * π)
D = C / π
Where π (pi) is approximately equal to 3.14159.
For example, if the diameter of a circle is 10 cm, the radius would be 5 cm (10 cm / 2). Conversely, if the radius is 3 cm, the diameter would be 6 cm (3 cm * 2). By understanding these relationships, you can easily find the radius and diameter of any circle with the information available.