Geometry: Finding the radius of a circle

To find the radius of a circle, we need to know the diameter of the circle. The diameter is a straight line that passes through the center of the circle and connects two points on the circumference. In this case, the given diameter is 8.4 cm.

Step 1: Understanding the concept of diameter and radius

- The diameter is the longest chord in a circle and it passes through the center.
- The radius is the distance from the center of the circle to any point on the circumference. It is half the length of the diameter.

Step 2: Calculating the radius using the formula

The formula to find the radius of a circle is:

Radius = Diameter / 2

Given that the diameter is 8.4 cm, we can substitute this value into the formula to find the radius:

Radius = 8.4 cm / 2 = 4.2 cm

Step 3: Conclusion

Therefore, the radius of the circle is 4.2 cm.

Summary

- The diameter of a circle is a straight line that passes through the center and connects two points on the circumference.
- The radius of a circle is the distance from the center to any point on the circumference. It is half the length of the diameter.
- To find the radius, we can use the formula: Radius = Diameter / 2.
- In this case, the given diameter is 8.4 cm. By substituting this value into the formula, we find that the radius is 4.2 cm.

Remember, practice is key to understanding and mastering geometry concepts!