SOLUTION: Prove the theorem that states that if AD/DB=AE/EC, then DE||BC

Question 1019001: Prove the theorem that states that if AD/DB=AE/EC, then DE||BC
Answer by ikleyn(52781) (Show Source): You can put this solution on YOUR website!
.
Prove the theorem that states that if AD/DB=AE/EC, then DE||BC
----------------------------------------------------------

The Theorem formulation is as follows:


   If in a triangle a straight line connects two sides and cuts off proportional segments in the triangle sides, 
   then this straight line is parallel to the third side of the triangle. 


See the lesson In a triangle a straight line parallel to its side cuts off a similar triangle in this site, Theorem 2.

RELATED QUESTIONS
In the figure if de||bc and ad=ae,then prove that abc is an isosceles... (answered by richard1234)

IN A DIAGRAM AD=BD=AE AND DE=EC PROVE THAT... (answered by Alan3354)

given triangle ABC and segment DE, if AD =2, DB =3, AE =4 and EC =4, is DE parallel to... (answered by nycsub_teacher)

given that db=3, ae=2, and ec=6, find... (answered by fractalier)

Right angle triangle that has a line drawn parallel to the base line of the triangle.... (answered by venugopalramana)

I have two problems that I need help: Problem #1: Prove triangle ABC is congruent... (answered by venugopalramana)

In triangle ABC,D and E are points on the sides AB and AC respectively such that DE... (answered by MathLover1)

21) if AD =1, DB=x, AE=x, and EC=x+2, find... (answered by Nate)

If AD=2,DB=x-1,AE=x and EC=x+2, find... (answered by aliafzal14,JBarnum)