Download
theorem n.
Skip this Video
Loading SlideShow in 5 Seconds..
Theorem PowerPoint Presentation

Theorem

119 Vues Download Presentation
Télécharger la présentation

Theorem

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Theorem A quadrilateral is a parallelogram if and only if the diagonals bisect each other.

  2. The diagonals bisect each other. Line segment DE is congruent to line segment EB & line segment AE is congruent to line segment EC. What am I trying to prove?

  3. ABCD is a parallelogram What is the given information?

  4. I have triangles. If I can prove that triangle ABE and triangle DEC are congruent then I can show that line segment DE is congruent to line segment EB & line segment AE is congruent to line segment EC because of CPCTC. First I have to show that the two triangles are congruent. What do I know?

  5. Since I know that ABCD is a parallelogram then I can say that AB is parallel to DC. I can use the theorem about parallel lines. How do I do that?

  6. I can say that these two triangles are congruent because of ASA. I showed all of the requirements. Because I showed that triangle ABE and triangle DEC are congruent, I can state that DE is congruent to EB & AE is congruent to EC. Thus the two diagonal bisect each other. Conclusion