Page 1 of 2 12 LastLast
Results 1 to 15 of 16

Math Help - Help in proving these two line segments are congruent?

  1. #1
    Newbie Crayola's Avatar
    Joined
    Jul 2011
    From
    San Francisco
    Posts
    20

    Help in proving these two line segments are congruent?

    Hello,

    I need help proving BF is congruent to ED.

    Givens:
    Angle FBC is congruent to Angle EDA
    The parallel sides of the parallelogram are congruent

    http://i55.tinypic.com/fvihj8.jpg
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Crayola View Post
    Hello,

    I need help proving BF is congruent to ED.

    Givens:
    Angle FBC is congruent to Angle EDA
    The parallel sides of the parallelogram are congruent


    using the fact that ABCD is a parallelogram along with the ASA postulate, you should be able to show triangle FBC congruent to triangle EDA ... then segments BF and ED are congruent because they are corresponding sides.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie Crayola's Avatar
    Joined
    Jul 2011
    From
    San Francisco
    Posts
    20

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by skeeter View Post
    using the fact that ABCD is a parallelogram along with the ASA postulate, you should be able to show triangle FBC congruent to triangle EDA ... then segments BF and ED are congruent because they are corresponding sides.
    Well wouldn't that be for if we are trying to solve for triangle ACD and ABC?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Crayola View Post
    Well wouldn't that be for if we are trying to solve for triangle ACD and ABC?
    same result ... make a choice and go w/ it.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie Crayola's Avatar
    Joined
    Jul 2011
    From
    San Francisco
    Posts
    20

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by skeeter View Post
    same result ... make a choice and go w/ it.
    But how would proving triangle ACD and ABC prove that DH and KF are congruent?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Crayola View Post
    But how would proving triangle ACD and ABC prove that DH and KF are congruent?
    what are you talking about? your original post said this ...

    I need help proving BF is congruent to ED
    where are points H and K on your diagram?
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie Crayola's Avatar
    Joined
    Jul 2011
    From
    San Francisco
    Posts
    20

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by skeeter View Post
    what are you talking about? your original post said this ...



    where are points H and K on your diagram?
    Sorry I got confused. Yes it should've been BF and ED.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454

    Re: Help in proving these two line segments are congruent?

    Follow Math Help Forum on Facebook and Google+

  9. #9
    MHF Contributor Also sprach Zarathustra's Avatar
    Joined
    Dec 2009
    From
    Russia
    Posts
    1,506
    Thanks
    1

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Crayola View Post
    Hello,

    I need help proving BF is congruent to ED.

    Givens:
    Angle FBC is congruent to Angle EDA
    The parallel sides of the parallelogram are congruent

    http://i55.tinypic.com/fvihj8.jpg


    Angle FBC is congruent to angle EDA - given.

    BC=AD - The parallel sides of the parallelogram are congruent

    Angle BCA is congruent to angle CAD - WHY?


    From the above we can conclude that:

    triangle FBC congruent to triangle EDA. (ASA)

    So, BF=ED (corresponding sides on congruent to triangles).
    Follow Math Help Forum on Facebook and Google+

  10. #10
    Newbie Crayola's Avatar
    Joined
    Jul 2011
    From
    San Francisco
    Posts
    20

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Also sprach Zarathustra View Post
    Angle FBC is congruent to angle EDA - given.

    BC=AD - The parallel sides of the parallelogram are congruent

    Angle BCA is congruent to angle CAD - WHY?


    From the above we can conclude that:

    triangle FBC congruent to triangle EDA. (ASA)

    So, BF=ED (corresponding sides on congruent to triangles).
    Alright, thank you! And for isn't Angle BCA is congruent to angle CAD because of the definition of an angle bisector?
    Follow Math Help Forum on Facebook and Google+

  11. #11
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Crayola View Post
    Alright, thank you! And for isn't Angle BCA is congruent to angle CAD because of the definition of an angle bisector?
    no
    Follow Math Help Forum on Facebook and Google+

  12. #12
    Newbie Crayola's Avatar
    Joined
    Jul 2011
    From
    San Francisco
    Posts
    20

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by skeeter View Post
    no
    Huh?
    Follow Math Help Forum on Facebook and Google+

  13. #13
    MHF Contributor Also sprach Zarathustra's Avatar
    Joined
    Dec 2009
    From
    Russia
    Posts
    1,506
    Thanks
    1

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Crayola View Post
    Huh?
    Read carefully!

    Parallelogram - Wikipedia, the free encyclopedia
    Follow Math Help Forum on Facebook and Google+

  14. #14
    Newbie Crayola's Avatar
    Joined
    Jul 2011
    From
    San Francisco
    Posts
    20

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Also sprach Zarathustra View Post
    Oh because of the alternate interior angles....
    Follow Math Help Forum on Facebook and Google+

  15. #15
    MHF Contributor Also sprach Zarathustra's Avatar
    Joined
    Dec 2009
    From
    Russia
    Posts
    1,506
    Thanks
    1

    Re: Help in proving these two line segments are congruent?

    Quote Originally Posted by Crayola View Post
    Oh because of the alternate interior angles....
    Indeed!
    Follow Math Help Forum on Facebook and Google+

Page 1 of 2 12 LastLast

Similar Math Help Forum Discussions

  1. Line segments
    Posted in the Geometry Forum
    Replies: 1
    Last Post: February 3rd 2009, 08:19 AM
  2. Congruent Segments
    Posted in the Geometry Forum
    Replies: 2
    Last Post: December 12th 2008, 04:32 PM
  3. Replies: 2
    Last Post: October 27th 2008, 07:31 PM
  4. Help me please! 3D Line Segments
    Posted in the Calculus Forum
    Replies: 3
    Last Post: December 19th 2007, 03:45 PM
  5. Please help, line segments
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: April 18th 2007, 05:31 PM

Search Tags


/mathhelpforum @mathhelpforum