\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry}

\usepackage{tikz}
\usepackage{tikz-cd}

\begin{document}

\begin{tikzcd}
T \arrow[dr,dotted,"{(x,y)}" description]
  \arrow[drr,"x",out=60, in=120]
  \arrow[ddr,"y"',bend right]\\
& X\times_Z Y \arrow[r,"p"]\arrow[d,"q"'] & X \arrow[d,"f"]\\
& Y \arrow[r,"g"',hook,two heads]           & Z
\end{tikzcd}


\newpage


\begin{tikzpicture}[scale=2]

	\foreach \x in {0,1,...,5} {
		\foreach \y in {0,...,3} {
			\filldraw[fill=blue] (\x,\y) circle[radius=0.4];
		};
	};
\end{tikzpicture}

\begin{tikzpicture}[scale=3]
	\draw[very thick] (0,0) \foreach \i in {0.3,0.6,...,1.5}
	  {-- (\i,\i^2) };
\end{tikzpicture}


\newpage

\begin{tikzpicture}

	\pgfmathsetmacro{\angle}{120}
	
	\colorlet{coscolor}{blue!60}
	\colorlet{sincolor}{red!60}
	\tikzset{structureline/.style={black,thin}}
	
	\draw[lightgray] (-5,-5) grid (5,5);
	
	
	\filldraw[thick,fill=green!20,draw=green] 
(0,0) -- (1/3*4,0) arc[radius=1/3*4, start angle=0, end angle=\angle] node[below=0.5cm] {\(\angle^\circ\)} -- cycle;

	\draw[->,structureline] (0,-5) -- (0,5);
	\draw[->,structureline] (-5,0) -- (5,0);
	\draw[structureline] (0,0) circle[radius=4];
	
	\draw[structureline] (0,0) -- (\angle:4);
	\draw[coscolor] (0,0) -- node[below] {\(\cos(\angle^\circ)\)} (4*cos{\angle},0);
	\draw[thick,sincolor] (4*cos{\angle},0) -- node[right] {\(\sin(\angle^\circ)\)} (\angle:4);
	
\end{tikzpicture}

\newpage
\begin{tikzpicture}[scale=3]
	\coordinate (A) at (1,1);
	\coordinate (B) at (3,1.5);
	
	\draw[blue!20!red,line width=4pt] (0,0) -- (A) -- (2,0) -- cycle;

	
	\draw[very thick,green!60,dotted] (B) circle[x radius = 0.7cm, y radius = 1.2cm];
	
	\filldraw[fill=purple,draw=blue,line width=2pt] (B) arc[radius = 1cm, start angle=0, end angle=90] -- (A) --cycle;
	
	\filldraw[fill=pink, line width=3pt] (0,0) rectangle (2,-1);
	
	\draw[line width=2pt,>->] (1,0.5) -- (3,0);

\end{tikzpicture}

\end{document}