SOLUTION: I have an isosceles triangle: On top of the triangle is a line with points A and B.The triangle is labeled with E on top, C on bottom left and D on bottom right. Under the parallel

Algebra ->  Geometry-proofs -> SOLUTION: I have an isosceles triangle: On top of the triangle is a line with points A and B.The triangle is labeled with E on top, C on bottom left and D on bottom right. Under the parallel      Log On


   

Question 1141290: I have an isosceles triangle: On top of the triangle is a line with points A and B.The triangle is labeled with E on top, C on bottom left and D on bottom right. Under the parallel line are the numbers 1 and 2 to the top left and top right of the triangle.
I am so confused.
How to write a two column proof:
Given: Line AB is parallel to line CD; line EC is congruent to line ED
Prove: Angle 1 is congruent to angle 2.
Found 3 solutions by Alan3354, MathLover1, math_helper:
Answer by Alan3354(69443) About Me  (Show Source):
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Given: Line AB is parallel to line CD; line EC is congruent to line ED
Prove: Angle 1 is congruent to angle 2.
1. AB ||+CD............given
2.EC congruent +ED............given
3. <ECD congruent <CDE.........................the Isosceles Triangle Theorem
4.<ECD congruent <2.................... Alternate Interior Angles are equal
5.<CDE congruent <1....................Alternate Interior Angles are equal
6. <1 congruent <2..............transitive property



Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
Small correction to MathLover1's solution:

Step 4 should read  "ECD is congruent to angle 1,   alternate interior angles are equal"

And similarly,  Step 5 should be  "CDE is congruent to angle 2,   alternate interior angles are equal"