![在此处输入图片描述](https://i.stack.imgur.com/pBuQa.png)
\documentclass{article}
\usepackage{pgfplots}
\usetikzlibrary{intersections,angles,quotes}
\usepgfplotslibrary{fillbetween}
%\pgfplotsset{compat=1.17}
\begin{document}
\begin{tikzpicture}[scale=3]
%grid lines
% \draw[]
% (-1.4,-1.4) grid (1.4,1.4);
% \filldraw[
% fill=blue!20,
% draw=red!50
% ]
% (0,0) -- (3mm,0mm)
% arc [
% start angle=0,
% end angle=30,
% radius=3mm]
% -- cycle;
%axes
\draw[->] (-1.5,0) -- (1.5,0) coordinate (x axis);
\draw[->] (0,-1.5) -- (0,1.5) coordinate (y axis);
%axes label
\node [right]at (1.5,0)(x){$x$};
\node [above]at (0,1.5){$y$};
%circle
% \draw (0,0) circle [
% radius=1cm
% ];
%triangle height
% \draw[
% very thick,
% orange
% ]
% (30:1cm) -- node[
% left=1pt,
% fill=white
% ]
% {$\sin \alpha$} (30:1cm |- x axis);
%triangle base
\path (30:1.2cm |- x axis)coordinate(a);
\draw[ultra thick,blue](a) -- node[below]{$t$}(0,0);
%intersection
\path [name path=upward line] (a) -- ++(0,1.5);
\path [name path=sloped line] (0,0) -- node [left=4pt,fill=white]
{$n$} (30:1.2cm);
\draw [name intersections={of=upward line and sloped line, by=t}]
[very thick,red]
(a) -- node [right=1pt,fill=white]
{$p$} (t);
\draw (0,0) -- (t);
%x-ticks
% \foreach \x/\xtext in {-1,
% -0.5/-\frac{1}{2},
% 1}
% \draw (\x cm,1pt) -- (\x cm,-1pt) node[
% anchor=north,
% fill=white
% ]
% {$\xtext$};
%y-ticks
% \foreach \y/\ytext in {-1,
% -0.5/-\frac{1}{2},
% 0.5/\frac{1}{2},
% 1}
% \draw (1pt,\y cm) -- (-1pt,\y cm) node[
% anchor=east,
% fill=white
% ]
% {$\ytext$};
%arc angle
\draw (x) coordinate (A)--
(0,0) coordinate (B)--
(t) coordinate (C)
pic [
draw,
red,
"$\alpha$",
angle radius=9mm
]
{angle};
\end{tikzpicture}
\end{document}