先解决原始问题

注意
\tkzGetAngle(angleADG)与
\tkzGetAngle{angleADG}看文档的例子:

所以,你只要把\tkzGetAngle(angleADG)替换为\tkzGetAngle{angleADG}即可
\documentclass[border=5pt]{standalone}
\usepackage{tkz-euclide}
\begin{document}
\begin{tikzpicture}
% ===== 定义点 =====
\tkzDefPoints{0/0/C, 4/0/E}
\tkzDefTriangle[two angles=23 and 37](C,E)
\tkzGetPoint{B}
\tkzDefPointBy[rotation=center B angle -90](C)
\tkzGetPoint{A}
\tkzDefPointBy[rotation=center B angle 90](E)
\tkzGetPoint{D}
\tkzCalcLength(B,D)
\tkzGetLength{BDlen}
\tkzDefPointWith[linear normed, K=\BDlen](B,A)
\tkzGetPoint{G}
\tkzFindAngle(A,D,G)
\tkzGetAngle{angleADG}%<-注意花括号
\tkzDefPointBy[rotation=center B angle \angleADG](A)
\tkzGetPoint{f}
\tkzInterLL(B,f)(A,D)
\tkzGetPoint{F}
% ===== 绘制图形 =====
\tkzDrawPolygon[thick](B,C,E)
\tkzDrawSegments[thick](A,B D,B A,C D,E A,D D,G B,F G,F)
\end{tikzpicture}
\end{document}一个workaround:
如果只要用一次,那么也可以直接用\tkzAngleResult,这样可以不用再\tkzGetAngle多写一行...

\documentclass[border=5pt]{standalone}
\usepackage{tkz-euclide}
\begin{document}
\begin{tikzpicture}[font=\small]
% ===== 定义点 =====
\tkzDefPoints{0/0/C, 4/0/E}
\tkzDefTriangle[two angles=23 and 37](C,E)
\tkzGetPoint{B}
\tkzDefPointBy[rotation=center B angle -90](C)
\tkzGetPoint{A}
\tkzDefPointBy[rotation=center B angle 90](E)
\tkzGetPoint{D}
\tkzCalcLength(B,D)
\tkzGetLength{BDlen}
\tkzDefPointWith[linear normed, K=\BDlen](B,A)
\tkzGetPoint{G}
\tkzFindAngle(A,D,G)
% \tkzGetAngle(angleADG)
\tkzDefPointBy[rotation=center B angle \tkzAngleResult](A)
\tkzGetPoint{f}
\tkzInterLL(B,f)(A,D)
\tkzGetPoint{F}
% ===== 绘制图形 =====
\tkzDrawPolygon[thick](B,C,E)
\tkzDrawSegments[thick](A,B D,B A,C D,E A,D D,G B,F G,F)
\end{tikzpicture}
\end{document}


























问 tkz-euclide 宏包中如何获取未知角的度数并用在另一个角的绘制中