Let 
and 
denote two directly similar
figures in the plane, where 
corresponds to 
under the given similarity. Let 
, and define 
. Then 
is also directly similar to 
.
Fundamental Theorem of Directly Similar Figures
See also
Directly Similar, Finsler-Hadwiger TheoremExplore with Wolfram|Alpha
References
Detemple, D. and Harold, S. "A Round-Up of Square Problems." Math. Mag. 69, 15-27, 1996.Eves, H. Solution to Problem E521. Amer. Math. Monthly 50, 64, 1943.Referenced on Wolfram|Alpha
Fundamental Theorem of Directly Similar FiguresCite this as:
Weisstein, Eric W. "Fundamental Theorem of Directly Similar Figures." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/FundamentalTheoremofDirectlySimilarFigures.html