R
Symbol  Format  Data 

R  Code Point 
U+0052 
TeX 
R 

SVG 
The capital Latin letter R is used in mathematics to represent the set of real numbers. Usually, the letter is presented with a "doublestruck" typeface when it is used to represent the set of real numbers.
The Latin letter r is used in math as a variable. It appears in geometric equations as a variable to represent the radius of a circle.
The set of real numbers symbol is a Latin capital R presented in doublestruck typeface.