Diameter

What is a Diameter?

A diameter is a special straight line that goes through the middle of a circle. It starts at one side of the circle, passes right through the center, and ends at the other side. This line is the longest you can draw inside a circle!

Fun Facts About Diameters

All diameters in the same circle are the same length. This length is always twice as long as the radius, which is the distance from the center of the circle to its edge.

People use a special symbol ⌀ to show diameter. For example, “⌀ 55 mm” means the diameter is 55 millimeters.

Where Else Do We See Diameters?

We can also talk about the diameter of a sphere, which is a round object like a ball. The idea of a diameter can even help describe other shapes, not just circles!