Coxeter - Theorem 3.33
Theorem: If ABCF is prospective to A'B'C'F' and H(AB, CF), then H(A'B', C'F'). We can see this represented in the geogebra file when using the point R.
Garden Problem TEL311
modul15-C2_goodman_smak santo paulus jember
show that triangle is one-fifth of large square