Show that if A, B, C, D,
E are five points in a line, then
(A,B;C,D)
(A,D;C,E)=
(A,B;C,E). This looks prettier if we write
(A,B;C,D) as (:BD:). It then says: (:BD:)*(:DE:)=(:BE:). How can we prove this statement?

A) By using the properties of points on a line
B) By using the properties of parallel lines
C) By using the properties of perpendicular lines
D) By using the properties of intersecting lines