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\begin{document}

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\section*{puzzles by topic}

\hypertarget{puzzles_by_topic}{}\section*{{Puzzles by Topic}}\label{puzzles_by_topic}

The purpose of this page is to sort the puzzles by the techniques needed to solve them. The various techniques are grouped into categories and ordered roughly by complexity. Alongside each technique are the puzzles that can be solved using (primarily) just that technique. Then at the end of each category there is a list of those puzzles that just use techniques from that category. Finally, there is a list of those puzzles that use techniques from that category and earlier categories.

Puzzles may appear more than once as they can have multiple ways of being solved. The categorisation is somewhat arbitrary and depends on what I felt was the primary techniques used in a solution. If a solution used an advanced technique, I probably didn't regard simple concepts as being noteworthy.

In the endnotes for the page for each topic is a list of the pages that link to it. Any that end in \emph{solution} or \emph{techniques} indicate a puzzle page. If mentioned in the \emph{techniques} page then I've classified it as a key technique. If just in the \emph{solution} page then I've needed it in a solution but have not regarded it as sufficient to note in the listed techniques. This list is automatically generated by the wiki software and sometimes is not complete.

\hypertarget{basic_angles}{}\subsection*{{Basic Angles}}\label{basic_angles}

\begin{itemize}%
\item [[angles on a straight line]]


\item [[angles at a point]]


\item [[vertically opposite]]



\end{itemize}
\hypertarget{angles_in_parallel_lines}{}\subsection*{{Angles in Parallel Lines}}\label{angles_in_parallel_lines}

\begin{itemize}%
\item [[angles and parallel lines]]

\end{itemize}
\hypertarget{shapes}{}\subsection*{{Shapes}}\label{shapes}

\begin{itemize}%
\item [[triangle]]




\item [[equilateral triangle]]




\item [[isosceles triangle]]




\item [[right-angled triangle]]


\item [[square]]




\item [[rectangle]]




\item [[parallelogram]]




\item [[trapezium]]




\item [[quadrilateral]]


\item [[angles of a polygon]]


\item [[pentagon]]




\item [[hexagon]]




\item [[regular polygon]]




\item [[circle]]




\item [[sector]]


\item [[lune]]




\item [[equation of a shape]]




\item Various Shapes




\item With previous categories





\end{itemize}
\hypertarget{measures}{}\subsection*{{Measures}}\label{measures}

\begin{itemize}%
\item [[Pythagoras]]




\item [[area]]




\item [[Heron's formula]]


\item [[dissection]]




\item [[gradients]]


\item [[parallelogram law]]




\item [[parallelogram identity]]


\item With previous categories





\end{itemize}
\hypertarget{transformations_and_symmetry}{}\subsection*{{Transformations and Symmetry}}\label{transformations_and_symmetry}

\begin{itemize}%
\item [[congruent]]




\item [[similarity]]




\item [[symmetry]]




\item [[transformation]]




\item [[tessellation]]




\item [[bisection]]


\item Various Transformations and Symmetry




\item With previous categories





\end{itemize}
\hypertarget{circle_theorems}{}\subsection*{{Circle Theorems}}\label{circle_theorems}

\begin{itemize}%
\item [[chord]]


\item [[angle between a radius and tangent]]




\item [[angle in a semi-circle]]




\item [[angle at the circumference is half that at the centre]]




\item [[angles in the same segment]]




\item [[cyclic quadrilateral]]


\item [[intersecting chords theorem]]




\item [[alternate segment theorem]]


\item Various Circle Theorems




\item With previous categories





\end{itemize}
\hypertarget{trigonometry}{}\subsection*{{Trigonometry}}\label{trigonometry}

\begin{itemize}%
\item [[trigonometry]]




\item [[cosine rule]]


\item [[sine rule]]




\item [[sine formula for the area of a triangle]]


\item [[compound angle formulae]]


\item Various Trigonometry




\item With previous categories





\end{itemize}
\hypertarget{algebra}{}\subsection*{{Algebra}}\label{algebra}

\begin{itemize}%
\item [[quadratics]]


\item [[quadratic equations]]


\item [[difference of two squares]]


\item With previous categories





\end{itemize}
\hypertarget{other_techniques}{}\subsection*{{Other Techniques}}\label{other_techniques}

\begin{itemize}%
\item [[hidden line technique]]


\item [[invariance principle]]




\item With previous categories





\end{itemize}


\end{document}