In the triangle ABC, D and E are the points on the sides of AB and AC respectively, and De is parallel to BC, be and DC intersect at O, and the line AO and BC intersect at M

In the triangle ABC, D and E are the points on the sides of AB and AC respectively, and De is parallel to BC, be and DC intersect at O, and the line AO and BC intersect at M

The intersection of AO and de and K
DK/CM=OD/OC=DE/BC=AD/AB
DK/BM=AD/AB
BM=CM