Plot[Sin[x],{x,0,0.2},PlotLegends->"sin"]

Plot[Sin[x], {x, 0, 0.2},
 PlotLegends -> Placed[LineLegend[{"sin"}, LegendFunction -> Frame,
    LegendMarkerSize -> {{55, 10}}], {0.8, 0.2}], Frame -> True]