The line CD is parallel to AB and crosses the angle BOA so that O,B,D lie on the same line and so do O,A,C. If OA=2, AC=4 and BD=6, determine the length of OB.  Choose the correct choice from the following
A) 3
B) 4
C) 5
D) 6
E) 7
Solution:   The lines 3B and CD are parallel, so by the intersect theorem, we have   OB/BD=O3/3C, or OB=O3/3C.BD=2/4.6=3   3nswer 3
<result>A</result>
The line CD is parallel to AB and crosses the angle BOA so that O,B,D lie on the same line and so do O,A,C. If OA=2, AC=4 and BD=6, determine the length of OB.