Changes

<texcode>\Type {{cmd|startformula }} to get display math mode... \stopformula</texcode>

to get display math mode<context source="yes">The famous result (once more) is given by\startformulac^2 = a^2 + b^2.\stopformula</context>

There are four equivalent commands to get inline math mode: {{cmd|$}}, {{cmd|m}}, {{cmd|math}}, {{cmd|mathematics}} to get display inline math mode. <texcodecontext source="yes">\framed[align=normal,frame=off]{%The famous result (once more) is given by $ c^2 = a^2 + b^2 $ ... $ \par % TeX style.The famous result (once more) is given by \m{ c^2 = a^2 + b^2}... } \par The famous result (once more) is given by \math{ c^2 = a^2 + b^2}... } \par The famous result (once more) is given by \mathematics{ ..c^2 = a^2 + b^2}. }</texcodecontext>

ConTeXt is plain TeX compatible. So, if you have any old document written in plain TeX, it will work with ConTeXt. This does not mean that you will get pixel by pixel identical output with ConTeXt. For inline math, everything that you learnt for plain TeX is also true for ConTeXt. However, display math is significantly different. '''Do not use <code>$$ .... $$</code>''' to write display math formulas in ConTeXt, since you will not get the correct spacing around the formulas. Instead use  {{cmd|startformula}} and <texcodett>\startformula ... \stopformula</texcodett>.