r̄
Symbol  Format  Data 

r̄  Code Point  U+0072 
TeX  \bar{r} 

SVG 
The r bar symbol.
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 combining macron is a unicode character used to draw a macron (horizontal bar) over the symbol it is combined with.