Products of Perspectivities
- GeoGebra Materials Team
Given three distinct points A, B, and C on a line, and three distinct points A", B", and C" on another line, constuct the intersection B' of AB" and A"B, and construct the intersection C' of AC" and A"C. Line B'C' is the axis of the projectivity. A' is the intersection of AA" and B'C'. To find the image of any point X, construct A"X. Let X' be the intersection of B'C' and A"X. Construct AX'. X" is the intersection of AX' and B"C".