(* Sachin Patel, Dot product  *)

Manipulate[ Module[{vv = v, ww, q}, ww = w; q = vv.ww;
Graphics[{ 
  {RGBColor[0, 1, 0], PointSize[0.04], Point[{0, 0}]},
   Locator[Dynamic[v], ImageSize -> 40], 
   Locator[Dynamic[w], ImageSize -> 40],
  {FontSize -> 20, Text["Dot Product", {3.5, 5}]},
  {FontSize -> 12, Text[v, {-3.8, 3.9}]},
  {FontSize -> 15, Text["\!\(\*OverscriptBox[RowBox[{\" \", \"v\"}], \"\[RightVector]\"]\)", {-3.8, 4.3}]},
  {FontSize -> 12, Text[w, {-3.8, 2.9}]}, {FontSize -> 15, Text["\!\(\*OverscriptBox[\"w\", \"\[RightVector]\"]\)", {-3.8, 3.3}]},
  {RGBColor[1, 0, 0], Thickness[0.01], Dynamic[Arrow[{{0, 0}, v}]]}, 
  {RGBColor[0, 0, 1], Thickness[0.01], Dynamic[Arrow[{{0, 0}, w}]]}}, 
  Axes -> True, Ticks -> True, PlotRange -> 5, PlotLabel -> Grid[{{Row[{"\!\(\*OverscriptBox[ RowBox[{\" \", \"v\"}], \
\"\[RightVector]\"]\)\[ThinSpace].\[ThinSpace]\!\(\*OverscriptBox[\"w\
\", \"\[RightVector]\"]\) = ", q}]}}], ImageSize -> {400, 400}]],
 {{v, {1., 0.}}, {-3, -3}, {3, 3}, Locator, Appearance -> None},
 {{w, {-2., 1.}}, {-3, -3}, {3, 3}, Locator, Appearance -> None}
]