Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Gabylovesyou

  • one year ago

Write an indirect proof to show that a rectangle has congruent diagonals. Be sure to create and name the appropriate geometric figures. This figure does not need to be submitted.

  • This Question is Closed
  1. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @ganeshie8 @phi @AccessDenied

  2. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Here is what an indirect proof means http://regentsprep.org/Regents/math/geometry/GP3b/indirectlesson.htm

  3. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok.. so i would first start with A rectangle doesn't have congruent diagonals

  4. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yes. That is as far as I got so far.

  5. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    lol! what happens next ? ;s

  6. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    draw a picture of a rectangle, label the sides , show the right angles. draw in a diagonal

  7. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1396376755171:dw|

  8. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    show the angles are all 90º

  9. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1396376914251:dw|

  10. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    the first thing that comes to mind is using pythagoras to find the length of a diagonal that leads to a direct proof. maybe we can tweak it to make in indirect.

  11. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok

  12. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    |dw:1396377047759:dw|

  13. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    does that make sense (so far ?)

  14. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes

  15. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    we could do the same thing for the other diagonal |dw:1396377220075:dw|

  16. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    if the diagonals are not equal to each other, that means a^2+b^2 ≠ a^2 + b^2 and that would only happen if we were not allowed to use the pythagorean theorem. But we have a right triangle (with 90º angle) so we are allowed. therefore our assumption that the diagonals are different must be wrong. that sure sounds convoluted, but it's the best I can come up with.

  17. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    the equal sign thing means does not equal ?

  18. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yes, ≠ means does not equal

  19. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok so i tried doing it in my own words... im going to put it and then delete it

  20. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @phi

  21. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @phi DONT LEAVE ME haha

  22. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    I would change that means that a^2 + b^2 does not equal a^2 + b^2 if we are not allowed to that means that a^2 + b^2 does not equal a^2 + b^2 SO we are not allowed

  23. Gabylovesyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    thanks

  24. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.