SOLUTION: I need help with my geometery proofs. Given: BF is parrallel to CD Prove: AB/AC=BF/CD (ab over ac is equal to bf over cd) This is a 2 column proof. Picture: One little tr

Question 255370: I need help with my geometery proofs.
Given: BF is parrallel to CD
Prove: AB/AC=BF/CD (ab over ac is equal to bf over cd)
This is a 2 column proof.
Picture: One little triangle is inside of a bigger triangle. Both triangles share the same vertex angle.
Statements:
1. BF is parrallel to CD.
2. Angle 1 is congruent to Angle C, Angle 3 is congruent to Angle C.
3. Angle A is congruent to Angle A.
4. Triangle ABF is similar to Triangle ACD.
5. AB/AC=BF/CD
Reasons:
1. Givens
2. Corresponding angles are congruent.
3. Congruence of angles is reflexsive.
4. Angle Angle similarity
5. Def of similar Angles.
Thanks so much!
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
I would have mentioned parallel lines intersected by a transversal forms angles which are congruent.
We have line AC intersecting BE and CD
and line AD intersecting lines BE and CD
Since (given) BE is parallel to CD, then angles ABE and ACD are congruent and angles AEB and ADC are congruent.
triangles CAD and BAE share angle BAE all three angles are congruent .
Since all three angles are congruent the triangles are similar.
since the triangles are similar their corresponding sides are proportional
therefore blah blah QED
PS you didn't say where angle 1 and angle 3 are
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