# How to insert a mathematic formula in a Graphics in TraditionalForm?

If a type Style[x^2 + y^2 <= 9, Red, 20] I get:

But if I include that in a plot or graphic, mathematic function appear as:

How can I get the mathematic formula in previous style?

You need to override the default FontFamily used in Graphics:
Graphics[

You can set an option so that all Text objects in graphics are displayed in "Times" for the duration of the front end session, so that one doesn't have to repeatedly add the FontFamily directive to every graphic:
SetOptions[
$FrontEndSession, InsetBoxOptions->{DefaultBaseStyle->{FontFamily->"Times"}} ]  For example: Graphics[{Text[x^2+y^2==1]}, PlotLabel->BesselJ[n,x], ImageSize->100]  If you want to make this permanent, then replace $FrontEndSession with \$FrontEnd. An alternative is to modify the "Graphics" style in the stylesheet.