Jennifer Wilson recently shared some neat activities on what she calls Hopewell triangles. I made this sketch to illustrate these triangles in general.[br][br]See:[br]Hopewell - Right Triangle [url]http://easingthehurrysyndrome.wordpress.com/2013/06/18/hopewell-geometry-right-triangle/[/url][br]Hopewell - Similarity [url]http://easingthehurrysyndrome.wordpress.com/2013/06/18/hopewell-geometry-similarity/[/url][br][br]The problem sheet (pdf)[br][url]http://www.map.mathshell.org/materials/download.php?fileid=499[/url]

More GeoGebra at [url=mathhombre.blogspot.com]mathhombre.blogspot.com[br][br][/url]20250416修改自：[url=https://www.geogebra.org/u/goldenj]John Golden[/url] — 2013年6月20日 - 上午12:12 的 [url=https://www.geogebra.org/m/aMN972e4]Folded Rectangle – Geogebra镜像站 (www.geogebra.org)[br][br][/url][url=https://www.geogebra.org/m/aMN972e4]折叠矩形 – GeoGebra --- Folded Rectangle – Geogebra镜像站 (www.geogebra.org)[/url]

A=(0,0)[br]B=(4,0)[br]a=直线(A,B)[br]b=垂线(B,a)[br]c=垂线(A,a)[br]C=描点(b)[br]d=垂线(C,b)[br]D=交点(c,d)[br]poly1=多边形(B,C,D,A)[br]线段(B,C,poly1)[br]线段(C,D,poly1)[br]线段(D,A,poly1)[br]线段(A,B,poly1)[br][b][color=#ff0000]D'[/color][/b]=描点(poly1)[br]e=中垂线(D'，D)[br]F=交点(e,d1)[br]F'=对称(F,e)[br]C'=对称(C.e)[br]G=交点(e,b1)[br]poly2=多边形(F, D', C',G)[br]线段(F,D', poly2)[br]线段(D', C', poly2)[br]线段(C',G,poly2)[br]线段(G,F,poly2)[br]H=交点(e,c1)[br]poly3=多边形(F,D',H)[br]线段(F,D',poly3)[br][br]A'=对称(A.e)[br]I=交点(e,a1)[br]poly4=多边形(A',I,H,D')[br]线段(A',1,poly4)[br]线段(1,H,poly4)[br]线段(H,D',poly4)[br]线段(D',A',poly4)[br]poly5=多边形(F,A,B,C,H)[br]线段(F,A.poly5)[br]线段(A,B,poly5)[br]线段(B,C,poly5)[br]线段(C,H,poly5)[br]线段(H,F,poly5)[br]j=线段(F,D)[br]k=线段(D,H)[br]l=线段(I,A)[br]m=线段(A,D)[br]m=线段(D,H)[br]poly6=多边形(B,I,H,C)[br]线段(B,1,poly6)[br]poly7=多边形(A,B,G,F)

p=线段(D,C)[br]q=线段(C,G)[br]r=线段(D'.C)[br]s=线段(D'.B)[br]u=向量(D,D')[br][br]α=角度(D,H,I)[br]β=角度(H,I,A)[br]E=交点(e_3, b_3)[br]Y=角度(B,E, D')[br]角度(D'.H,C)[br]E[br]n[br]K[br]入[br]角度(H,F,D)[br]角度(D,H,F)[br]角度(F,G,D')[br]角度(G,F,D)[br]角度(A,F,D')[br]角度(F,D',B)[br]角度(D', G, C')[br]角度(C,G,F)[br]值0