Answer:
all vertices on the two lines=60+36=96
Step-by-step explanation:
line a has 6 points and line b has 4 points
now each triangle drawn has on vertices on one line and two vertices on another line:
the line with six points :C(6,2) six points , has two vertices
C(6,2)=6*5/2*1=30/2=15 pairs of points
each pair connected to one point on the other line (4 points)
4*15=60 vertices
now let us consider the two lines on the other line with 4 points:
6c(4,2)=6*((4*3(/2))=6*6=36 vertices
all vertices on the two lines=60+36=96