Similar

$\begin{figure}\begin{center}\BoxedEPSF{DirectlySimilar.epsf scaled 800}\quad\BoxedEPSF{InverselySimilar.epsf scaled 800}\end{center}\end{figure}$

Two figures are said to be similar when all corresponding Angles are equal. Two figures are Directly Similar when all corresponding Angles are equal and described in the same rotational sense. This relationship is written $A\sim B$ . (The symbol $\sim$ is also used to mean ``is the same order of magnitude as'' and ``is Asymptotic to.'') Two figures are Inversely Similar when all corresponding Angles are equal and described in the opposite rotational sense.

References

Project Mathematics! Similarity. Videotape (27 minutes). California Institute of Technology. Available from the Math. Assoc. Amer.