如何在曲线路径上的三个等距点处绘制等长的切线？

Question

就像下面的弯曲三角形

我所能画的只是 MWE。

\documentclass[tikz]{standalone}
\begin{tikzpicture}
        \draw (0,0) -- (4.5,0) -- (6,2) -- (1.5,2) -- cycle;
        \draw [xshift=3cm,yshift=1cm] (0,0) ellipse (1.2 and .6);
        \draw [xshift=3cm,yshift=1cm,->,teal] (0,.6) -- (.6,.6);
        \draw [xshift=3cm,yshift=1cm,->,teal] (1.2,0) -- (1.9,0);
        \draw [xshift=3cm,yshift=1cm,->,teal] (0,-.6) -- (.6,-.6);
        \draw [xshift=3cm,yshift=1cm,->,teal] ({-1.2*cos(30)},{-.6*sin(30)}) --++ (.6,0) node [above] {$v^a$};
        \draw [xshift=3cm,yshift=1cm,->,teal] ({-1.2*cos(30)},{.6*sin(30)}) --++ (.6,0);
        \shade [xshift=3cm,yshift=1cm,ball color=teal] (-1.2,0) circle (.06);
\end{tikzpicture}