#【015_ビュフォンの針】コマ大数学科
\begin{tikzpicture}
\fill [orange!90!black] (-0.2,-0.2) rectangle (4.2,4.2);
% 縦の線
  \foreach \x in {0,2,4}
  {\draw [very thick](\x,-0.2) -- (\x,4.2);
  \draw (\x,-0.2) -- (\x,-1.2);
  }
% 距離をとる
  \draw [<->](0,-0.5)--(2,-0.5);
  \draw [<->](2,-0.5)--(4,-0.5);
  \node at (1,-0.8) {10cm};
  \node at (3,-0.8) {10cm};
  
% 横の線
  \foreach \x in {0,2,4}
  {\draw (-0.2,\x) -- (4.2,\x);
  \draw (4.2,\x)--(5,\x);
  }
% 距離をとる
  \draw [<->](4.5,0)--(4.5,2);
  \draw [<->](4.5,2)--(4.5,4);
  \node at (5,1) {10cm};
  \node at (5,3) {10cm};
  
% コイン
  \filldraw [fill=yellow!20!white] (1.3,1) circle (0.3) node [font=\tiny]{コイン};
  \draw (1,0.3)--(1,1);
  \draw (1.6,0.3)--(1.6,1);
  \draw [<->](1,0.5)--(1.6,0.5);
  \node at (1.3,0.5)[below,font=\tiny]{3cm};
\end{tikzpicture}