# Drawing an angle in simple tikz

I'm tyring to make a very simple tikz drawing for an orthogonal projection of two vectors, but I can't make a round angle. Can someone help me with that please?

My current code is the following:

\begin{center}
\begin{tikzpicture}[scale=0.2]
\tikzstyle{every node}+=[inner sep=0pt]

\draw [->, line width=1.2] (0,0) -- (30,0);
\draw (22,0) node [below, yshift=-0.3cm] {$u$};

\draw [->, red, line width=1.2] (0,-2) -- (15,-2);
\draw (7.5,-3) node [below, text=red] {$p$};

\draw [->, line width=1.2] (0,0) -- (15,15);
\draw (7.5,7.5) node [above left, yshift=0.5cm] {$v$};

\draw [dotted, line width=0.75] (15,15) -- (15,0);

\draw [black] (13,0) -- (13,2);
\draw [black] (13,2) -- (15,2);

\draw [-, bend left=80] (3,3.5) -- (7,0);
\draw (6,2.5) node [above right] {$\Theta$};

\end{tikzpicture}
\end{center}


which produces the following drawing:

You can use the calc library for the projection and the angles library for the angles.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{angles,calc}
\begin{document}
\begin{tikzpicture}[scale=0.2,nodes={inner sep=0pt},>=latex]
\draw [<->, line width=1.2] (30,0) coordinate (u)
--  node[pos=0.3,below=1ex] {$u$} (0,0) coordinate(o)
-- node[pos=0.5,above left=1ex] {$v$} (15,15) coordinate (v);
%
\draw [dotted, line width=0.75] (v) -- ($(o)!(v)!(u)$) coordinate (p);
%
\draw [->, red, line width=1.2] (0,-2) -- node[pos=0.5,below=1ex] {$p$}
($(p)+(0,-2)$);
%
\pic[draw,angle radius=3em,angle eccentricity=1.3,pic text={$\Theta$}]{angle=u--o--v};