Google Classroom
GeoGebraGeoGebra Classroom

門格海綿

A1={polygon(A,B,C,D)} A2=Join(dilate(A1,1/3,A),dilate(A1,1/3,B),dilate(A1,1/3,C),dilate(A1,1/3,D),dilate(A1,1/3,(A+B)/2),dilate(A1,1/3,(B+C)/2),dilate(A1,1/3,(C+D)/2),dilate(A1,1/3,(D+A)/2))