Three Dimensional Geometry Part 4

Let the line L1 be parallel to the vector −3

∧

i

+2

∧

j

+4

∧

k

and pass through the point (2,6,7), and the line L2 be parallel to the vector 2

∧

i

+

∧

j

+3

∧

k

and pass through the point (4,3,5). If the line L3 is parallel to the vector −3

∧

i

+5

∧

j

+16

∧

k

and intersects the lines L1 and L2 at the points C and D, respectively, then |

→

CD

|2 is equal to: