# Equilateral Triangle

• Oct 3rd 2008, 04:58 AM
magentarita
Equilateral Triangle
In equilateral triangle ABC, AB = 14. Find the perimeter of the triangle that joins the midpoints of the sides of triangle ABC.
• Oct 3rd 2008, 07:01 AM
Nacho
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 (Crying)
• Oct 3rd 2008, 10:03 AM
Soroban
Hello, magentarita!

Quote:

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.

• Oct 3rd 2008, 10:05 AM
masters
Quote:

Originally Posted by magentarita
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
• Oct 3rd 2008, 04:48 PM
magentarita
wonderful....
Quote:

Originally Posted by Soroban
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.

• Oct 3rd 2008, 04:49 PM
magentarita
pictures....
Quote:

Originally Posted by masters
See diagram. Add the sides of the little triangle inside the big triangle

How do you make such drawings?
• Oct 4th 2008, 01:22 PM
masters
Quote:

Originally Posted by magentarita
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.
• Oct 4th 2008, 10:27 PM
magentarita
Tell me...
Quote:

Originally Posted by masters
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?
• Oct 5th 2008, 11:58 AM
masters
Quote:

Originally Posted by magentarita
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.