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Math Help - Equilateral Triangle

  1. #1
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    Equilateral Triangle

    In equilateral triangle ABC, AB = 14. Find the perimeter of the triangle that joins the midpoints of the sides of triangle ABC.
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  2. #2
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    If the new triangle maked, is DEF and too is equilateral and your sizes are the 1/2 of the size of the triangle ABC

    sorry for my bad english
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    Hello, magentarita!

    In equilateral triangle ABC, AB = 14.
    Find the perimeter of the triangle that joins the midpoints of the sides of \Delta ABC.
    There is a theorem that says:

    The line segment joining the midpoints of two side of a triangle
    . . is parallel to and one-half the length of the third side.
    Code:
                      C
                      *
                    *  *
                  *     *
              P *--------* Q
              *           *
            *              *
        A *  *  *  *  *  *  * B

    We have . PQ \parallel AB,\quad \overline{PQ} \,=\,\frac{1}{2}(\overline{AB})

    . . and this is true for any triangle.

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  4. #4
    A riddle wrapped in an enigma
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    Quote Originally Posted by magentarita View Post
    In equilateral triangle ABC, AB = 14. Find the perimeter of the triangle that joins the midpoints of the sides of triangle ABC.
    See diagram. Add the sides of the little triangle inside the big triangle
    Attached Thumbnails Attached Thumbnails Equilateral Triangle-tri.bmp  
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  5. #5
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    wonderful....

    Quote Originally Posted by Soroban View Post
    Hello, magentarita!

    There is a theorem that says:

    The line segment joining the midpoints of two side of a triangle
    . . is parallel to and one-half the length of the third side.
    Code:
                      C
                      *
                    *  *
                  *     *
              P *--------* Q
              *           *
            *              *
        A *  *  *  *  *  *  * B
    We have . PQ \parallel AB,\quad \overline{PQ} \,=\,\frac{1}{2}(\overline{AB})

    . . and this is true for any triangle.
    Another wonderful reply.
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  6. #6
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    pictures....

    Quote Originally Posted by masters View Post
    See diagram. Add the sides of the little triangle inside the big triangle
    How do you make such drawings?
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  7. #7
    A riddle wrapped in an enigma
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    Quote Originally Posted by magentarita View Post
    How do you make such drawings?
    My drawings aren't sophisticated like some others that you might have seen on this forum. I simply use Microsoft Paint. Simple, I know. But it seems to serve the purpose...so long as the drawings don't get too complicated.
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  8. #8
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    Tell me...

    Quote Originally Posted by masters View Post
    My drawings aren't sophisticated like some others that you might have seen on this forum. I simply use Microsoft Paint. Simple, I know. But it seems to serve the purpose...so long as the drawings don't get too complicated.
    What are the steps for using microsoft paint?
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  9. #9
    A riddle wrapped in an enigma
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    Quote Originally Posted by magentarita View Post
    What are the steps for using microsoft paint?
    It's found under "Program" "Accessories". There's a help tab at the top and a toolbar on the left.
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