Question: I am trying to draw something like this in overleaf using Tikzpicture, I need assistance

[![enter image description here](https://i.stack.imgur.com/2lwme.png)](https://i.stack.imgur.com/2lwme.png)

Answer: 
This is relative simple problem. You only need to make yourself a little bit familiar with TikZ package. It has very detailed (consequently huge) documentation, but for start is sufficient to read the first *Tutorial* or [A very minimal introduction to TikZ](http://cremeronline.com/LaTeX/minimaltikz.pdf) and see examples of its use [TeXample](https://texample.net/)

With use of the TikZ library `angles` and scale of picture:

```
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{angles}

\begin{document}
    \begin{figure}
    \centering
\begin{tikzpicture}[
myangles/.style = {draw, 
                   angle radius = #1 mm},
myangles/.default = 4
                    ]
%%%% first triangle
\draw   (0,0) coordinate[label= left:A] (a) -- 
        (3,0) coordinate[label=right:B] (b) -- 
        (1,2) coordinate[label=above:C] (c) -- cycle;
\pic [myangles]     {angle = b--a--c}; 

\pic [myangles]     {angle = a--c--b};
\pic [myangles=5]   {angle = a--c--b};

\pic [myangles]     {angle = c--b--a};
\pic [myangles=5]   {angle = c--b--a};
\pic [myangles=6]   {angle = c--b--a};
%%%% second triangle: scaled of the first
    \begin{scope}[xshift=44mm, scale=2]
\draw   (0,0) coordinate[label= left:D] (a) --
        (3,0) coordinate[label=right:E] (b) --
        (1,2) coordinate[label=above:F] (c) -- cycle;
\pic [myangles]     {angle = b--a--c};

\pic [myangles]     {angle = a--c--b};
\pic [myangles=5]   {angle = a--c--b};

\pic [myangles]     {angle = c--b--a};
\pic [myangles=5]   {angle = c--b--a};
\pic [myangles=6]   {angle = c--b--a};
    \end{scope}
\end{tikzpicture}
    \caption{Triangles in Tikz}
    \end{figure}
\end{document}

```

[![enter image description here](https://i.stack.imgur.com/ASwnz.png)](https://i.stack.imgur.com/ASwnz.png)
Here is something to start with.

How to properly make the right angle mark see [here](https://tex.stackexchange.com/a/79999/224762).

```
\documentclass[border=3mm]{article}

\usepackage{tikz}
\usepackage{caption}

\newcommand*{\rechterWinkel}[3]{% #1 = point, #2 = start angle, #3 = radius
    \draw[shift={(#2:#3)}] (#1) arc[start angle=#2, delta angle=90, radius = #3];

}

\begin{document}

    \begin{figure}
        \centering

    \begin{tikzpicture}     

        \draw (0,0) -- (1,1) -- (3,0) -- cycle;
    \node[xshift=-2mm](A) at (0,0) {A};
    \node[yshift=2mm](C) at (1,1) {C};
    \node[xshift=2mm](B) at (3,0) {B};
    \rechterWinkel{0.2,0}{1}{.2} %A

    \rechterWinkel{1,1.05}{-127}{.2} %B
    \rechterWinkel{1,1.04}{-127}{.25} %B

    \rechterWinkel{2.8,0}{90}{.1} %C   
    \rechterWinkel{2.75,0}{90}{.128} %C
    \rechterWinkel{2.7,0}{90}{.155} %C

        \end{tikzpicture}

    \begin{tikzpicture}     

    \draw (0,0) -- (2,2) -- (5,0) -- cycle;
    \node[xshift=-2mm](D) at (0,0) {D};
    \node[yshift=2mm](F) at (2,2) {F};
    \node[xshift=2mm](E) at (5,0) {E};

    \end{tikzpicture}

    \caption{Triangle in Tikz}
    \end{figure}

\end{document}

```

[![enter image description here](https://i.stack.imgur.com/mVUXC.png)](https://i.stack.imgur.com/mVUXC.png)