How to prove that the midpoint of the given line segment lies on another line segment?












0












$begingroup$


I have the following question with me:



In a triangle ABC D and E lie on sides BC and AB respectively. F lies on AC such that EF is parallel to BC, G lies on side BC such that EG lies parallel to AD. Let M and N be midpoints of AD and BC respectively. Prove that the midpoint of GF lies on line MN. Also prove that $frac{EF}{BC} + frac{EG}{AD} = 1$



How do I solve this question? I do not want to use coordinate geometry or vectors to solve this euqstion.



The only thing I figured out is that FG is also parallel to AB. Does it help?










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    I have the following question with me:



    In a triangle ABC D and E lie on sides BC and AB respectively. F lies on AC such that EF is parallel to BC, G lies on side BC such that EG lies parallel to AD. Let M and N be midpoints of AD and BC respectively. Prove that the midpoint of GF lies on line MN. Also prove that $frac{EF}{BC} + frac{EG}{AD} = 1$



    How do I solve this question? I do not want to use coordinate geometry or vectors to solve this euqstion.



    The only thing I figured out is that FG is also parallel to AB. Does it help?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      I have the following question with me:



      In a triangle ABC D and E lie on sides BC and AB respectively. F lies on AC such that EF is parallel to BC, G lies on side BC such that EG lies parallel to AD. Let M and N be midpoints of AD and BC respectively. Prove that the midpoint of GF lies on line MN. Also prove that $frac{EF}{BC} + frac{EG}{AD} = 1$



      How do I solve this question? I do not want to use coordinate geometry or vectors to solve this euqstion.



      The only thing I figured out is that FG is also parallel to AB. Does it help?










      share|cite|improve this question











      $endgroup$




      I have the following question with me:



      In a triangle ABC D and E lie on sides BC and AB respectively. F lies on AC such that EF is parallel to BC, G lies on side BC such that EG lies parallel to AD. Let M and N be midpoints of AD and BC respectively. Prove that the midpoint of GF lies on line MN. Also prove that $frac{EF}{BC} + frac{EG}{AD} = 1$



      How do I solve this question? I do not want to use coordinate geometry or vectors to solve this euqstion.



      The only thing I figured out is that FG is also parallel to AB. Does it help?







      geometry euclidean-geometry triangle






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 6 at 7:34









      Michael Rozenberg

      108k1895200




      108k1895200










      asked Jan 6 at 6:29









      saisanjeevsaisanjeev

      1,025312




      1,025312






















          1 Answer
          1






          active

          oldest

          votes


















          2












          $begingroup$

          Let $frac{AF}{AC}=frac{AE}{AB}=x$ and $K$ be a midpoint of $FG$.



          Thus, $$frac{BG}{BD}=frac{BE}{AB}=1-x$$ and from here
          $$vec{KN}=frac{1}{2}left(vec{FC}+vec{GB}right)=frac{1}{2}left((1-x)vec{AB}+(1-x)vec{DB}right)=frac{1}{2}(1-x)vec{MN},$$
          which says $Kin MN.$



          The second is true because $$frac{EF}{BC}+frac{EG}{AD}=frac{AE}{AB}+frac{BE}{AB}=1.$$






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            thanks for the help, vectors did simplify a lot of stuff. However, as I mentioned can I get a solution without coordinate geometry or vectors?
            $endgroup$
            – saisanjeev
            Jan 6 at 9:53











          Your Answer





          StackExchange.ifUsing("editor", function () {
          return StackExchange.using("mathjaxEditing", function () {
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
          });
          });
          }, "mathjax-editing");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "69"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3063550%2fhow-to-prove-that-the-midpoint-of-the-given-line-segment-lies-on-another-line-se%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          2












          $begingroup$

          Let $frac{AF}{AC}=frac{AE}{AB}=x$ and $K$ be a midpoint of $FG$.



          Thus, $$frac{BG}{BD}=frac{BE}{AB}=1-x$$ and from here
          $$vec{KN}=frac{1}{2}left(vec{FC}+vec{GB}right)=frac{1}{2}left((1-x)vec{AB}+(1-x)vec{DB}right)=frac{1}{2}(1-x)vec{MN},$$
          which says $Kin MN.$



          The second is true because $$frac{EF}{BC}+frac{EG}{AD}=frac{AE}{AB}+frac{BE}{AB}=1.$$






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            thanks for the help, vectors did simplify a lot of stuff. However, as I mentioned can I get a solution without coordinate geometry or vectors?
            $endgroup$
            – saisanjeev
            Jan 6 at 9:53
















          2












          $begingroup$

          Let $frac{AF}{AC}=frac{AE}{AB}=x$ and $K$ be a midpoint of $FG$.



          Thus, $$frac{BG}{BD}=frac{BE}{AB}=1-x$$ and from here
          $$vec{KN}=frac{1}{2}left(vec{FC}+vec{GB}right)=frac{1}{2}left((1-x)vec{AB}+(1-x)vec{DB}right)=frac{1}{2}(1-x)vec{MN},$$
          which says $Kin MN.$



          The second is true because $$frac{EF}{BC}+frac{EG}{AD}=frac{AE}{AB}+frac{BE}{AB}=1.$$






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            thanks for the help, vectors did simplify a lot of stuff. However, as I mentioned can I get a solution without coordinate geometry or vectors?
            $endgroup$
            – saisanjeev
            Jan 6 at 9:53














          2












          2








          2





          $begingroup$

          Let $frac{AF}{AC}=frac{AE}{AB}=x$ and $K$ be a midpoint of $FG$.



          Thus, $$frac{BG}{BD}=frac{BE}{AB}=1-x$$ and from here
          $$vec{KN}=frac{1}{2}left(vec{FC}+vec{GB}right)=frac{1}{2}left((1-x)vec{AB}+(1-x)vec{DB}right)=frac{1}{2}(1-x)vec{MN},$$
          which says $Kin MN.$



          The second is true because $$frac{EF}{BC}+frac{EG}{AD}=frac{AE}{AB}+frac{BE}{AB}=1.$$






          share|cite|improve this answer











          $endgroup$



          Let $frac{AF}{AC}=frac{AE}{AB}=x$ and $K$ be a midpoint of $FG$.



          Thus, $$frac{BG}{BD}=frac{BE}{AB}=1-x$$ and from here
          $$vec{KN}=frac{1}{2}left(vec{FC}+vec{GB}right)=frac{1}{2}left((1-x)vec{AB}+(1-x)vec{DB}right)=frac{1}{2}(1-x)vec{MN},$$
          which says $Kin MN.$



          The second is true because $$frac{EF}{BC}+frac{EG}{AD}=frac{AE}{AB}+frac{BE}{AB}=1.$$







          share|cite|improve this answer














          share|cite|improve this answer



          share|cite|improve this answer








          edited Jan 6 at 7:31

























          answered Jan 6 at 6:46









          Michael RozenbergMichael Rozenberg

          108k1895200




          108k1895200












          • $begingroup$
            thanks for the help, vectors did simplify a lot of stuff. However, as I mentioned can I get a solution without coordinate geometry or vectors?
            $endgroup$
            – saisanjeev
            Jan 6 at 9:53


















          • $begingroup$
            thanks for the help, vectors did simplify a lot of stuff. However, as I mentioned can I get a solution without coordinate geometry or vectors?
            $endgroup$
            – saisanjeev
            Jan 6 at 9:53
















          $begingroup$
          thanks for the help, vectors did simplify a lot of stuff. However, as I mentioned can I get a solution without coordinate geometry or vectors?
          $endgroup$
          – saisanjeev
          Jan 6 at 9:53




          $begingroup$
          thanks for the help, vectors did simplify a lot of stuff. However, as I mentioned can I get a solution without coordinate geometry or vectors?
          $endgroup$
          – saisanjeev
          Jan 6 at 9:53


















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Mathematics Stack Exchange!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          Use MathJax to format equations. MathJax reference.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3063550%2fhow-to-prove-that-the-midpoint-of-the-given-line-segment-lies-on-another-line-se%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          Bressuire

          Cabo Verde

          Gyllenstierna