\documentclass{standalone} \usepackage{tikz} \title{Strassnitzky's formula} \begin{document} \begin{tikzpicture} \draw[help lines, color=gray!30, dashed] (0,0) grid (10,8); \draw[-,fill=gray, opacity=0.5] (0,0) -- (10,0) -- (10,2) -- (0,0); \draw[-,fill=gray!50!white, opacity=0.5] (0,0) -- (10,2) -- (9,7) -- (0,0); \draw[-,fill=gray, opacity=0.5] (0,0) -- (9,7) -- (8,8) -- (0,0); \draw[-,thick] (0,0) -- (8,0) -- (8,8) -- (0,0); \draw[rotate=-45] (0,1) arc (90:45:1); \draw[-] (9.8,0) -- (9.8,0.2) -- (10,0.2); \draw[-] (7.8,0) -- (7.8,0.2) -- (8,0.2); \coordinate(A) at (10,2); \coordinate(B) at (8,8); \draw[-,rotate around={13:(A)}] (10,2.2) -- (9.8,2.2) -- (9.8,2); \draw[-,rotate around={315:(B)}] (8.2,8) -- (8.2,7.8) -- (8,7.8); \end{tikzpicture} \end{document}