# Drawing Quarter-Circle

I have drawn a square as shown below. However, I need to draw a quarter-circle inside the square such that the radius of the quarter-circle is 1 and it the center is drawn in the bottom left. Please keep code minimal, I am a beginner.

\coordinate[label=below:$A$] (A) at (0,0);
\coordinate[label=:$B$] (B) at (0,1);
\coordinate[label=:$C$] (C) at (1,1);
\coordinate[label=below:$D$] (D) at (1,0);
\draw[] (0,0)--(0,1)--(1,1)--(1,0)--(0,0);


You can do that with

\draw (D) arc[start angle=0, end angle=90, radius=1];


This may or may not be self-explanatory. It draws a circular arc with radius 1 starting at the point D. start angle=0 means that it is the point on the circle at an angle of zero that is placed at D.

\documentclass[border=5mm]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\coordinate[label=below:$A$] (A) at (0,0);
\coordinate[label=:$B$] (B) at (0,1);
\coordinate[label=:$C$] (C) at (1,1);
\coordinate[label=below:$D$] (D) at (1,0);

\draw (A)--(B)--(C)--(D)--cycle;

\draw (D) arc[start angle=0, end angle=90, radius=1];
\end{tikzpicture}
\end{document}

• I like the simple answers. Why there is a little sign in the image at the bottom right? A cropping problem? May 10, 2019 at 21:29
• @Sebastiano No, a screenshot problem. It is the mouse cursor that is included in the screenshot. May 10, 2019 at 21:35
• Ah! Thank you so much! I think I get it now--such a simple answer as well! May 10, 2019 at 23:23

Another solution to the problem would be adding:

\draw[-] (1, 0) arc (0:90:1);


this will draw an arc from a circle of radius 1 from (1,0) to (0,1)