# Thread: area

1. ## area

I can get everything but the area can you help me?

2. Hello, jwein4492!

In the following diagram, NDBA is a rectangle,
$\displaystyle AN = NG,\;BF = DB,\;GD = 11,\;DF = 8\sqrt{2}$
What is the area of parallelogram $\displaystyle GDFA$ ?

Code:
      A           G      11     D
* - - - - - * - - - - - - *
|         *             * |
|       *         _   *   |
|     *         8√2 *     | x
|   *             *       |
| *             *         |
* - - - - - - * - - - - - *
A             F     x     B

We know the base of the parallelogram: .$\displaystyle GD = 11$

We need the height, $\displaystyle DB = x.$

Since $\displaystyle BF = DB,\;\Delta DBF$ is a 45° right triangle.

Using Pythagorus: .$\displaystyle x^2 + x^2 \:=\:\left(8\sqrt{2}\right)^2\quad\Rightarrow\quad 2x^2 \:=\:128\quad\Rightarrow\quad x^2 \:=\:64$

Therefore: .$\displaystyle x \:=\:8$

Got it?

3. ## but

I got all that I need to find the area.

4. ## still need the area of parallelogram

anyone out there???