## IGD: Area of a Parallelogram

*How Do You Find the Area of a Parallelogram?*

In a parallelogram, opposite sides are parallel and have the same length. This applet will show you how to divide the parallelogram into pieces, arrange them together to form a rectangle, and then use the formula for the area of a rectangle to find the area of the parallelogram.

Return to the *IGD: Areas* Overview.

*A*and

*B*to change the size and shape of the parallelogram.

Drag the red point to move the right half of the parallelogram. Move this piece to create a rectangle with the left half. Click the **Make Rectangle** box to be shown how a rectangle can be made from the parallelogram.

Click the **Show Dimensions** button to indicate the measurements needed to find the area.

The **Start Over** button resets the diagram.

Change the size and shape of the parallelogram by dragging points *A* and *B*. Then, drag the right half of the parallelogram to form a rectangle with the left half.

- What is the area of the rectangle that you get?
- Click the
**Show Dimensions**. What measurements of the parallelogram do you need in order to find its area?

Click the **Start Over** button, and repeat the investigation for parallelograms of other sizes.

- Are your conjectures true, regardless of the size of the parallelogram?
- Do all the parallelograms have the same area?