The figure below shows a trapezoid, ABCD, having side AB parallel to side DC. The diagonals AC and BD intersect at point O.

ABCD is a trapezoid with DC parallel to AB. Diagonals AC and DB intersect at point O.

If the length of AO is three times the length of CO, the length of DC is

three times the length of OC
three times the length of DO
one-third of the length of AC
one-third of the length of AB

Question

The figure below shows a trapezoid, ABCD, having side AB parallel to side DC. The diagonals AC and BD intersect at point O.

ABCD is a trapezoid with DC parallel to AB. Diagonals AC and DB intersect at point O.

If the length of AO is three times the length of CO, the length of DC is

 three times the length of OC
 three times the length of DO
 one-third of the length of AC
 one-third of the length of AB

krissysivan · Answer

attachment

krissysivan · Answer

i chose A. is it right? @Mrs.ambrose614

krissysivan · Answer

@jhonyy9 help

krissysivan · Answer

hello???

jhonyy9 · Answer

how you get this answer ? 

given that the length of AO = 3CO 

yes ?

krissysivan · Answer

im not sure, im really bad at math

jhonyy9 · Answer

from this result that BO = 3DO

jhonyy9 · Answer

bc. the diagonales of this trapezoid are congruent

krissysivan · Answer

so which answer choice would it be?

jhonyy9 · Answer

@3mar please your opinion here ?

3mar · Answer

Thank you @jhonyy9 

The idea is the similarity of the triangles ODC and OBA