# How to do these arrows with tikz?

I have a figure like the image:

And I want to draw these arrows like this image:

This is my code:

\usepackage{tikz}
\usepackage{tkz-euclide}
\usetkzobj{all}

\begin{figure}[h]
\centering
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzpicture}
%Definindo os vertices
%Vertice da reta da esquerda
\tkzDefPoint (0,0){A}
\tkzDefPoint (0,8){B}
%Vertices U1
\tkzDefPoint (1,0){C}
\tkzDefPoint (1,1.5){D}
%Vertices U2
\tkzDefPoint (4,6){E}
\tkzDefPoint (4,8){F}
%Chao1
\tkzDefPoint (-1.5,0){G}
\tkzDefPoint (6,0){H}
%Desenhando as retas
\draw (A) -- (B);
\draw (C) -- (D);
\draw (D) -- (E);
\draw (E) -- (F);
\draw (G) -- (H);
\end{tikzpicture}
\end{figure}

• You can make your code a little more efficient by combining some of the \draw commands: \draw (C) -- (D) -- (E) -- (F); – Annie Carter May 30 '18 at 1:23
• One way to get your arrows is to define their endpoints, as you have done with the other lines, and then put in lines tipped with arrows with code like \draw[-stealth] (P) -- (Q); – Annie Carter May 30 '18 at 1:26

I will not change the style you used to draw the diagram (I see no point in using tkz-euclide here), I will just add the arrows you want. The intersections library comes in handy to calculate the points of arrow tips. You draw long-enough equally spaced horizontal rays and let the library calculate their intersection points with the zigzag line. Then, you draw the arrows starting from the AB line towards the right till the corresponding intersection point.

\documentclass[10pt,a4paper]{article}
\usetkzobj{all}
\usetikzlibrary{intersections,arrows.meta}
\begin{document}

\begin{figure}[!htb]
\centering
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzpicture}[>= {Stealth[scale=2.5,inset=0pt,angle'=20]}]
%Definindo os vertices
%Vertice da reta da esquerda
\tkzDefPoint (0,0){A}
\tkzDefPoint (0,8){B}
%Vertices U1
\tkzDefPoint (1,0){C}
\tkzDefPoint (1,1.5){D}
%Vertices U2
\tkzDefPoint (4,6){E}
\tkzDefPoint (4,8){F}
%Chao1
\tkzDefPoint (-1.5,0){G}
\tkzDefPoint (6,0){H}
%Desenhando as retas
\draw (A) -- (B) (G) -- (H);
\draw[name path=zigzag] (C) -- (D) -- (E) -- (F);
\foreach \y in {0.5,1.3,...,7.8}{
\path[name path=ray] (0,\y) -- (9,\y);
\path[name intersections={of=zigzag and ray,by=p}];
\draw[->] (0,\y) -- (p);
}
\end{tikzpicture}
\end{figure}

\end{document}