In circle geometry, the radius and diameter are closely connected. Let’s break it down simply:

• Radius ($r$): This is the distance from the center of the circle to any point on the edge.

• Diameter ($d$): This measures the distance across the circle, going right through the center. It’s basically twice the radius.

You can remember their relationship with this easy formula:

$d = 2r$

If you know the diameter and want to find the radius, you can use this one:

$r = \frac{d}{2}$

Knowing how the radius and diameter relate helps in solving circle problems.

It’s super helpful in many geometry situations!