FrancophonIA/Vikidia-EnFr huggingface dataset:
In geometry, the radius of a circle or sphere is the shortest connection between the center and the boundary. It is half of the diameter.

r= d ÷ 2

d= 2 x r = d= r + r

r= Radius
d= Diameter

The relationship between the radius 





r




{\displaystyle {\displaystyle r}}

 and the circumference 





c




{\displaystyle {\displaystyle c}}

 of a circle is 




 
c
=
2
π
r
.


{\displaystyle ~c=2\pi r.}

The area 





A




{\displaystyle {\displaystyle A}}

 of a circle of radius 






r




{\displaystyle {\displaystyle r}}

 is 






 
A
=
π

r

2


.




{\displaystyle {\displaystyle ~A=\pi r^{2}.}}