# Question Video: Identifying the Radii of a Given Circle Mathematics • 11th Grade

Identify all the radii of circle ๐.

01:31

### Video Transcript

Identify all the radii of circle ๐.

Thereโs a few things we should think about here. The first thing is that when we name a circle circle ๐, itโs indicating to us that the point ๐ is the center of the circle. We also need to think about what is meant by radii. Radii is the plural form of the radius of a circle, and a radius is the distance from the center to the circumference of a circle. And the circumference is the outside edge of the circle. This means weโre looking for any line that starts at the center and goes out to the outside edge of the circle.

We see that here from ๐ to ๐บ, which makes line segment ๐๐บ a radius, we can start at the center ๐ and move out to the point ๐น, which makes the line segment ๐๐น a radius. The same thing is true if we start at the center ๐ and move out to the point ๐ธ, which makes line segment ๐๐ธ a radius. ๐น๐บ cannot be a radius of the circle as it does not start or end at the center. Itโs also worth noting that the line segment ๐น๐ธ goes through the point ๐ and we call that a diameter of the circle. However, the two segments that make up the diameter are both radii. For this circle ๐, the three radii we see are ๐๐บ, ๐๐น, and ๐๐ธ.