[Cleanup] Less hardcoding

Note: the angle is not 15 but rather 15.1 degrees!

src/sand-wedge-data/geometry.tex

@@ -9,16 +9,19 @@
 
 \begin{document}
 \begin{tikzpicture}[scale=12]
-  \pgfmathsetmacro{\hypot}{sqrt(1+.27^2)};
-  \pgfmathsetmacro{\ssin}{sin(15)};
-  \pgfmathsetmacro{\scos}{cos(15)};
-  \pgfmathsetmacro{\lsin}{sin(75)};
+  \pgfmathsetmacro{\rightleg}{0.27};
+  \pgfmathsetmacro{\leftleg}{1.00};
+  \pgfmathsetmacro{\hypot}{sqrt(\leftleg^2+\rightleg^2)};
+  \pgfmathsetmacro{\myangle}{atan(\rightleg/\leftleg)};
+  \pgfmathsetmacro{\ssin}{sin(\myangle)};
+  \pgfmathsetmacro{\scos}{cos(\myangle)};
+  \pgfmathsetmacro{\lsin}{sin(90-\myangle)};
 
   \coordinate (A) at (0,0);
   \node at (A) [left] {A};
   \coordinate (B) at (\hypot,0);
   \node at (B) [right] {B};
-  \coordinate (C) at (\lsin, .27*\lsin);
+  \coordinate (C) at (\lsin, \rightleg*\lsin);
   \node at (C) [above] {C};
 
   \draw (A)